My experience is that users can fail to see this box is ticked and end up with multiple anti-virus applications installed, which isn't ideal.
I think it's a big assumption on the part of Adobe to attempt to foist mcafee on users; by all means offer antivirus, but leave the box unticked. It should be opt in.
I'm with you, but... It ain't gonna change anytime soon. Oracle Systems (Java), VideoLan (VLC), Roxio, Corel... they ALL use "sponsored" installers or downloads, and they're ALL checked by default. Unless EVERYONE EVERYWHERE stops using EVERYTHING that has these downloads... all the complaints in the world won't make a bit of difference.
Adobe offests development and server costs by using these sponsored downloads, and they aren't likely to give that up.