To be honest I think that company must have the right to deny who they choose allow to advertise,
Yes. People should just move on and accept that these things happen on centralized platforms. If they don't want to list crypto ads, then let it be so. People in most cases won't even click on legitimate ads, because they don't say COME HERE AND WE'LL PROMISE YOU 50% RETURNS. We got rid of dirt mostly, and that's the positive side of this development. There are enough other crowded places to advertise on if needed.
We all know about the shitty low quality ICO's but I think instead of just banning all facebook is capable of checking the ads for credibility.
Too much of a hassle, because they very well know that it isn't rewarding. It was clear that the far majority of the ads were coming from illegitimate services, so the very few legitimate services that were advertising, but got burried under the insane load of scam ads, will not even bother spending time on it, so why would social media platforms do?