Babowa,
This type of criticism is not very warranted. Bittorrent is a valid P2P technology, even though because of its decentralization people use it for quite a bit of illegitimate activity. As for MacKeeper, the criticism and description of it as malware is also incorrect. Even though it is not the best software and has questionable advertising practices, it is not malware as many claim. This is false, just like people claiming Macs now have "viruses" because of recent malware outbreaks is false.
MacUpdate has been one of the few good software distribution resources for the Mac that does a pretty good job, similar to VersionTracker and CNET's Download.com (both of which have merged to the latter). If folks need to download updates or software for OS X, then they can go to any of these sites to get the files they need and be sure to not run into malware.
I'm certain that should an advertiser link to true malware for any of these sites, that the sites would immediately remove the links and issue profuse apologies and remedies for damage done. So far this has not happened, and should not happen. Since MacKeeper is legitimate software, even though people may frown upon it there is no reason to blacklist its advertisements and promote bias against it--that is up to the reviews and end users in discussion among themselves.