I'm glad that Avast works well for you. However, that is not the case for everyone. It has nothing to do with moving back, but to getting back to work, particularly when some issues do not seem to be resolved so quickly. Yes, it's great to have a forum with assistance from other users, but I'd also like to see an Avast programmer stop by every once in awhile and see the issues that have hit a number of us not so inexperienced computer users.
EVERY company has software releases that cause unforeseen problems. That is why pencils have erasers, and why operating systems have system restores, and users have backup programs, imaging software, etc.
I think one has to be practical in life, and software installations (even free ones) require an investment of time of the user: to understand how to install it, to understand its features and to get it to do what the user intends. When it doesn't, it wouldn't hurt to have the option to revert back to a previous build that was found to be working. Sometimes, simpler builds have less problems.
Addendum: While I appreciate the link to filehippo for previous Avast versions, I for one would ALWAYS want to download security products (antivirus, anti-spyware, MS patches, firewall software) DIRECTLY from the creator of the software for security reasons. One can't be too careful these days, what with hardware itself being susceptible to tampering (Seagate drives being a recent example).