I'm about to finish The Guns of August and Tuchman has been pretty critical of French, Moltke, and Joffre. Some of it I could chalk up to the challenges of coordinating gigantic forces without the benefit of modern communications technologies but the picture that she paints is one of leaders who seem almost criminally inept.
Joffre especially comes off poorly as a leader in the first month as he withheld information from the French government and his own commanders, ignored intelligence reports, resisted modernization of the military, and removed any number of officers from their positions for perceived "failings." John French's attitude towards Kitchener and the French commanders seems practically treasonous. Moltke seems to have been put in a tough spot and didn't fare it very well as he vacillated on the implementation of the Schlieffen Plan when confronted by his generals.
My academic background is anthropology and I've been in the US military but this is sort of my first real foray into the nitty gritty of those early 20th century conflicts. I've started reading Meyer's A World Undone and I imagine that will clear up a few things (he was definitely more clear on the state of affairs in the Balkans) but I wanted to know what you all think. Were these guys really as bad at their jobs as it seems or was Mrs. Tuchman being hasty in characterizing them as too headstrong for their own good?
While Tuchman's books in general make for good narrative, and Guns is considered a classic, Guns especially makes for very 'meh' history to say the least. French's decisions during the retreat were pretty controversial, but considering the losses taken by the BEF, the nature of the retreat itself, and what the consequences would have been if the BEF itself had been destroyed, while none of these exactly excuse his flagrant disregard for his ally's flank, I think it certainly places his decisions outside the realm of 'cowardice'.
Moltke was old, and he himself didn't exactly consider himself the best for the job, but as you say, he was dealt a pretty rough hand, and the situating of his HQ in Luxembourg didn't exactly help. I would, however, take issue with many of those characterizations of Joffre. While I can't speak to the withholding information (what exactly did he withhold?), the ignoring intel part I'm going to assume refers to continuing Plan XVII while the Germans were moving to the north. This I think is a mistake stemming from the fact that Plan XVII, Joffre, and really the French Army in 1914 in general is typically dumbed down and written off with the words Offense a l'outrance. Plan XVII was designed to 'push on to berlin', the French didn't believe in defense, etc. In reality, Plan XVII was laid out so that 2 French Armies would attack Germany in the only place it could be attacked, Alsace Lorraine, while three more would be held to the north bordering Belgium. The French fully expected a German attack through Belgium, and so the plan was to parry it with three armies while the two in the south established a position from which to flank the Germans. It was not simply a Berlin, as it is regularly depicted. Only problem was: a) The Germans were making their main thrust through northern Belgium, not southern Belgium as the French believed, and B) the Germans utilized their reserve divisions alongside regular divisions, meaning the invasion took place in much greater strength than the French anticipated. However, Joffre DID ditch Plan XVII, and took the decisions that set the stage for the Battle of the Marne.
As for:
resisted modernization of the military, and removed any number of officers from their positions for perceived "failings"
He did not block modernization; he expanded railways, modernized the fortress line in the south, championed aircraft, and oversaw the adoption of the Mle 1897 75mm Field Gun, the most modern piece of it's type in Europe in 1914. He successfully adopted an artillery program in April 1914, to equip the French army with modern heavy artillery pieces, and 1914 also saw a definite replacement uniform ordered, though it would not arrive until 1915 (the famous 'Horizon Blue' uniforms).
Finally, although some of his August dismissals were 'politically' motivated, he was in general getting rid of over-aged, incompetent, undynamic commanders, to bring in 'Fresh blood', which he did. Furthermore, he supported successful commanders like Foch, Castelnau, Franchet-Desperey, Fayolle and others, who would go on to lead France to victory.
or was Mrs. Tuchman being hasty in characterizing them as too headstrong for their own good?
TL;DR: essentially, Yes.