Completely agree, the spam is a turn off for the site. I assume if someone is smart enough to build a site like this, they know how to eliminate the spam but are just lazy.
1. What's up with that? Looks like testing bots, because most of the messages don't make sense at all.
2. They should mitigate these bots, because ultimately it will make the website annoying to visit.
I don't think they're testing bots; many seem to be linking to external sites or advertising something.
Maybe SRE related spam?
Looks like oldschool SEO farming by stuffing a bunch of reference links to their site all over the internet so the robots think that tons of people are linking to your site. Don't think it works as well anymore but still a common tactic.