They can't.
Please also keep in mind that emucr makes money off doing nothing but running other people's work through visual studio and uploading the result to a terribly designed web page crowded with ads. Using their builds actively encourages that behavior, and sort of makes me wish our emulator wasn't open-source to begin with - if it weren't for the upper sides of providing source code.
I'm aware that people want to tinker around with our new stuff - but for God's sake, it's really not /that/ hard to install Visual Studio yourself and follow our build instructions on the GitHub wiki. I don't even mind too much if you guys publish your builds after doing so, as long as you follow the license terms and don't start trying to make money off our work (which, even though permitted by our license, is at least morally condemnable).
And before anyone asks - no, providing builds ourselves is not a solution. I'd rather get stuff done than having to deal with the flood of user support requests which would ultimately come up, regardless of how many disclaimers we put alongside the builds.
It should be easy to build, but there's no .SLN file as old times and CMake it's isn't friendly for all people.