It also eliminates significant amounts of feedback that would be sent to you as the developer and instead splits your mindshare among you and whoever compiled your program and has the best SEO. In the worst case scenario, somebody compiles your program with a suboptimal set of optimization flags, or with a bad library, or any number of things, and it makes your program look terrible. People start posting that "Foosoft makes terrible software" because they downloaded a version that is terrible, and you get all the blame for that - do you think they'll even remember that they downloaded their binary from free-foosoft-binaries.com.net.mx.biz.cc?
I also take umbrage to calling this a 'donation'. If you get something in exchange for it that people who don't donate can't get, it isn't a 'donation', it is a purchase. Call it a purchase. Say you're buying the binaries. It isn't a "contribution", a "donation", or "feel good warm fuzzies", it is a cold hard transaction of cash for something of value.