Consider the facts that we have so far, ignoring innuendo, jumping to conclusions, broken inferences, and all the other things that make life fun:
1) Many people are reporting the same failure after downloading today's update.
2) We have someone from avast (Igor) who is actively trying to help, or at least was soliciting uploads of minidumps.
3) We are starting to get spotty reports in another thread(s) of a fix for this.
I fail to see how you can draw the conclusion that Avast has suddenly and without warning dropped support for 6 and 7. I can support the conclusion that this was a flawed update that wasn't tested as well as it could have been. I've been a coder for a loooong time, these things happen from time to time.
As to Avast 8 is the /worst thing ever/best thing ever/other/, meh, that's as may be. It's doesn't really have anything to do with the problem reported in this thread.
As to posts from members with high post counts, the only thing you know from that is that they've made a lot of posts. This may be because they are a long time, deeply involved member of the community whose opinion should be heard and respected, or it may mean that they're a yappy idiot who doesn't know when to shut up. There's no way for a casual observer to know.