Two other pieces of information would be great here.
1) What is the URL in question.
2) When you click the 'why not' link what does it say?
The other (possibly not relevant) question is whether or not you have any Google advertising or not on your site. I'm not suggesting that there is a 'pay for play' here, what I'm looking at is that when you use 'AdsenseForContent' or (AfC) the only way Google can know what sort of ads would make sense on your page is to crawl them first. If you had AfC ads on your page and Google wasn't crawling them, then that would suggest that your URLs are black listed for some reason. At Blekko our crawler tries to avoid sites that are either patently malicious (they've got known exploits in their pages) or on a list of malware/childporn sites, or have complex page structures that don't involve recursive crawling loops.
Your robots.txt is nothing but comments. It doesn't specify the URL of your sitemap. It does have a blanket disallow for all user agents for the root of your site. It is commented out (like everything else) but if that was ever uncommented that could be your problem.
I guessed your sitemap URL since it isn't in your robots.txt. You have every single page listed as being updated hourly. Even if that is true I wouldn't put that in there.
And what is your relationship to https://www.hirezstudios.com/smitegame/home ? I ask because it seems like you share a lot of material. Game studios get a bit twitchy about that when it isn't part of their PR plan.
Hmm, if that were the case I'd expect it to show up in the Transparency report though.
(I work at Google on webmaster issues)
Your site has a manual spam action probably based on something a previous owner had on it ( https://web.archive.org/web/20110202220759/http://smitecamp.... shows scraped Yahoo Answers content). You can see that in Webmaster Tools under Search Traffic / Manual Actions. Submitting a reconsideration request should do the trick.
1. Do you have a verified valid robots.txt that Google can read?
2. Does your verified valid robots.txt point to a verified valid sitemap or sitemap index?
3. Did your submit your verified valid sitemap or sitemap index to Google Webmaster Tools?
Based on the responses to this, I or someone else might be able to help you further. Good luck to you.