There was an element of that. Some people wanted to "push the Germans east" and sympathized with the idea of a war between the west and communism.

But mostly it was due to the (ultimately foolish) hope that if Germany was treated "fairly" then Germany would stop being expansionistic.

So to give context, a lot of people looked at the treaty of versailles that ended WW1, and they saw that it was pretty harsh on Germany.

Germany had to pay a lot of money, give up a lot of land, and couldn't even have a real military so was forced to be defenseless.

Also Germany was WRECKED by the great depression. A lot of people blamed this economic weakness on the unfair treatment from versailles and so had some sympathy for the Germans.

For example, basically the first military breach of the peace was Germany taking back control of the Rhineland (a part of Germany which was at that time being administered and controlled by France even though it was still recognised as being part of Germany). When Germany did this, people thought "fair enough, they are just taking back a piece of Germany".

Then later they demanded parts of Czechoslovakia that contained German people. So people thought "fair enough, that is basically part of Germany anyway".

Then they seized the rest of Czechoslovakia and people said "hey wait... stop that!"

Then they declared war on Poland and everyone said "WTF?!" and declared war on Germany.

Then there was the "false war" because even though the allies had declared war on Germany, they didn't really do anything.

Then Germany conquered France and Britain decided to take things seriously.

So some people thought that if we were to let Germany regain the land it once contained and allow it to become a "real" country again (i.e. have an army, regain sovereignty etc) then that would satisfy them. They were wrong about this.

A mix of sympathy for Germany and complacency among the allies until it was really far too late to stop Hitler.