Actually, let's go over the stuff koneko was freaking out about:
Release the Spyce was genuinely not very good and I'd have been more upset if it did well
Endro, Tonari no Kyuuketsuki-san, and Comic Girls all fall under the "comedies underperform" clause. Anime discs are really expensive, which means that something a few people are really into will do better than something a lot of people are moderately fond of, and comedies are generally on the wrong side of this
Harukana Receive was, again, not especially good. All the drama was dealt with early on, leaving most of the series bereft of any emotional weight
So, yeah, all of this is stuff that could be reasonably expected to sell poorly for reasons entirely unrelated to yuri