My guess is that it is probably not overtly malicious, but that people at Google are just responding to incentives. There are simply more incentives for Google to get things working 100% right in Chrome.

It is not to say that it is ok, though, as it could result in more people switching away from Firefox -- which is not a good thing for the web.

I, an enthusiast Firefox user, had to stop using Hangouts in Firefox because it could get excruciatingly slow (while fine in Chrome). Again, not saying it's Google's fault; it may be the case that with my configuration, Firefox is just generally slower than Chrome for the kind of fancy code that powers Hangouts. But they certainly did not try to make it run well for me, for lack of incentives. Many people (especially lay) would have responded by switching to Chrome. I responded by deactivating gmail chat and switching to Skype.