No one is proposing laws about who can hold given positions. There is no free speech angle here. What's happening on HN is exactly what our system wants to happen: answer speech you don't like with more speech!
There's a lot at stake here, which is why people are reacting so forcefully. What kind of values does the SV community have? What kind of values do Y Combinator and HN have? People are coming here because HN and Y Combinator very much helped make Dropbox what it is, and if that creation is now paying and giving prestige to a person who has gravely harmed the world, for bad reasons, a lot of people will object and are objecting to that.
A free society has the right to determine what it values. I hope our community decides to value ethics and humanitarianism. One way we can express those values is to speak out against companies that help criminals launder their reputations.