So, I have a couple of things on this. As someone who deals with the subject of the German Wehrmacht on a regular basis, I don't think "honorable" is the right category here to classify behavior. "Honorable" as a social category is one the Wehrmacht themselves used and since they themselves portrayed how they acted as honorable (nobody goes around saying "Well, I am the bad guy" save maybe James Bond villains), "honorable" as a category is pretty warped and distorted when it comes to Wehrmacht soldier behavior.

Anyways, I have written extensively about the Wehrmacht before here and here and the basic gist of it is that the Wehrmacht as an institution was highly implicated in war crimes and criminal conduct, starting from the top and going to the bottom levels.

For examples of said criminal conduct, I can only direct you to the above linked posts.

When it comes to the soldiers on the bottom levels of the Wehrmacht, the privates, sergeants etc., it is very important to keep in mind that the Wehrmacht as an institution did encourage its members to commit acts of violence and war crimes. I like to use the example of Serbia for this: In Serbia in 1941 the German Wehrmacht faced an uprisings by both communist Partisans and nationalist Chetniks. Having to divert most combat troops towards the Soviet Union, the occupational force in the country consisted of two Security Divisions and parts of a third Security Division, which was stationed in Croatia. These Security Divisions were made up mostly of older men (with average age of about 30) who had received comparatively little training and were thought to have a rather cozy up until the uprising broke out. This social make-up is important here because we are talking about people who had not been socialized in the Nazi system but rather had experienced a different socialization. They were also mostly Austrian, and this is a factor Wehrmacht commanders in Serbia used.

When the uprising broke out, the commanding general, Franz Böhme issued orders that said (I am translating here):

This is the country where in 1914 waves of German blood were spilled. You are the avengers of these dead. (...) The Serb in his Balkan mentality only speaks the language of violence.

A couple of days later they instituted a policy that for every dead German soldiers 100 civilians were to be shot and for every injured German soldiers 50 civilians were to be shot. Incised by the rhetoric of Serb-hatred, the troops carried out this orders with a lot of vigor and between September 1941 and December of the same year, the Wehrmacht shot over 20.000 civilians in Serbia, mostly on their own initiative without having to be prompted by higher commanders.

In one of these actions, Wehrmacht soldiers shot a group of about 300 Jews (they pretty much shot all male Jews of the country between September and December), who were not even Serbian but Austrian and German Jews who had tried to flee to Palestine in 1939 by boat but were held up by Yugoslav authorities along the Danube.

What is special about that and exemplifies the practice of the Wehrmacht in WWII: Older man from Austria, of whom some probably had been Social Democrats in the inter-war period given the popularity of that party, shot on their own initiative 300 male Jews from Austria because they were fighting communist Partisans on Serbia. This is absurd on first glance and only works when one takes into account that the Wehrmacht was successful in moving the frame of reference and legitimacy of their soldiers into a nationalsocialist direction. The soldiers who carried out these shootings saw sense in killing Austrian Jews as a means of fighting Serbian communists because for them, communists and Jews were inseparable from each other. This is imperative to keep in mind when talking about the Wehrmacht.

How deep this went is show in the eve's dropping protocolls from American and British POW camps where Allied security services listened in on the conversations between Wehrmacht members of all ranks. Harald Welzer and Sönke Neitzel as well as Felix Römer have dug through these protocols and shown that among the common rank and file soldiers violence against civilians as well as violence against Jews was accepted as a legitimate means of warfare when embedded in the frame of reference of fighting Partisans (which was how the Wehrmacht portrayed it mostly).

Römer cites from these protocols of a certain Feldwebel (Sergent) S., who was stationed first in the Soviet Union and then in France. S. argues that the Wehrmacht does have a "right of revenge" against the civilian population in case of Germans dying. S. sitting in Fort Hunt as POW explains his thinking to his comrades:

Partisans need to be mowed down like every warfaring power has ever done. We can only act energetically. (...) I have sworn myself, if we ever occupy France again, we must kill every male Frenchman between 14 and 60. Everyone of them I'll come across, I'll shot. That's what I am doing and that's what everyone of us should do.

His fellow POWs agreed.

So when you ask if they were evil or decent men caught up in a bad situation, the answer is neither. The Wehrmacht had 18.2 million soldiers in the field that represented German society pretty well to some extent. The Wehrmacht was also an institution deeply involved in Nazi crimes and had itself a policy of criminal conduct. It was very successful in creating a frame of reference in which these millions of members to an overwhelming decree were either willing to participate in war crimes or at least saw them as legitimate. This of course does not include all members and we known of people who saved Jews as well as people who deserted because they were unwilling to adopt the described frame of reference.

What is important to keep in mind is that it can't be said that they were just decent men caught up in something bad or were "just fighting for their fatherland". They were fighting for Nazi goals and knew about it. Most of them regarded the shooting of women and children as legitimate in Partisan warfare. And while a lot of this came from the Wehrmacht as an institution, it is important not to forget that a historical actor indeed does have also their own agency and some in the Wehrmacht used that agency to not go along with these policies. In the end though the majority went along, which doesn't make them evil (also because I don't know how to apply that category) but it makes people who were at least willing to accept passively atrocities on a huge scale.

Sources:

• Sönke Neitzel, Harald Welzer: Soldaten: On Fighting, Killing and Dying. The Secret World War II Transcripts of German POWs, 2012.

• Felix Römer: Der Kommissarbefehl. Wehrmacht und NS-Verbrechen an der Ostfront 1941/42, 2008.

• Felix Römer: Kameraden. Die Wehrmacht von innen, 2012.

as well as the above linked posts.