It's just a lazy effort by the OP to advertise their site. As others noted, they list some scams and don't list some known reputable sites. The site says "bitz.gg" when you open it. Looks like they rebranded to a different domain but didn't bother to change the references. Don't give them any traffic, not worth it.
It's true and didn't even add other dice site in their poll. It seems it's an advertising of their site. If not then they should just create q poll here in bitcointalk forum. Also, op did not yet answer the question about how did they come up with the site listed on their poll for voting (i'm curious).
Don't be curious with this kind of fake poll(s) and don't waste your time waiting a serious answer from Op.
The only purpose of it is to promote both their "poll site" and their gambling site, which in most cases (if not all) is scam.
As mentioned earlier, not worth it.
The website "Strawpoll" is most likely not owned by them. I've seen that site used many times in the past when someone wanted to make a quick poll and didn't have a forum that had that feature such as a Reddit post or Discord chat.
I do question however their selection of sites that they has chosen because a few of those are proven scams and many I've never heard off and there are a few legit ones. Sure its possible that they want to promote their site, however since they posted this poll publicily and want us to vote, most people will vote for the legit sites and not their site. And I don't think its that easy for them to just fudge the results on Strawpoll, what will they do? Keep changing their IP just to make a new vote, don't think so.
Like I said a few days back, just make a new thread on bitcointalk and use the Poll option instead and that way it would be more active and get more participants.