When it comes to anime, it is never about "deserve" or "not deserve" but whether the investors (sponsors) and producers are willing to put money into it or not. For mecha animes, it is all about the sponsors as that it promote political controversies in whichever way the one who puts the most money into the project sees fit as opposed to right or wrong as that is irrelevant.
----
When it comes to your issue in regards to ecchi animes, the creation of a second season is very different as that it depends on how popular the series is. The political mindset will be switched to a business mindset. Many ecchi animes turn out to have visual novels, figurines, mangas, doujin projects, and also all sort of accessories. Isn't that a lot of money? If an ecchi anime proves to be popular among the majority of people in Japan, it will no doubt receive a second season.
Although Kannagi have yet to receive a second season but as soon as people started paying visits to a shrine due to its close resemblances to Nagi's shrine in the anime, the shrine staff started making charms to be sold at nearby restaurants, convenience stores, and also on-site; it no doubt boosted tourism to the not-so-well-known shrine. However, a second season is most likely in development or at least, some more episodes to be released as a special ova set. On one occasion in which a particular volume of manga gave the impression that Nagi had a boyfriend whose name matches that of the author herself, some Kannagi fans gone on an outrage and started destroing their manga collections, as well as setting them ablaze. Although, this is a rather extreme case but it also indicates that people do take manga and anime somewhat seriously and do make a big deal out of it. And thus, popularity of the series in Japan is most important as opposed to whether it deserves a second season or not. And by the way, Kannagi is an ecchi love comedy even though on first impression, you would think it is more of a Shintoism fairytale but its nothing like that after an episode.
Personally, I have dropped Queen's Blade and never watched Kanokon but it appears that those two series are very popular, especially among males in Akihabara. There are visual novels and figurines, as well as plenty of doujinshi and other stuff. I dropped it as that I didn't really like the story or perhaps, watching the first episode of Queen's Blade wasn't enough. Considering that it will receive a second season, I have second thoughts of continuing the series. Kanokon, I never liked so I never watched. Sekirei is also getting a second season as that it is produced by the well-known and popular game maker, Square-Enix. Square-Enix had became rather popular over their two huge game series, Dragon Quest and Final Fantasy. The fact that an ecchi love comedy with supernatural elements produced by Square-Enix will no doubt become popular and thus, a second season is a good idea. To be honest, I was going to drop the first season of Sekirei after a few episodes if it wasn't from Square-Enix. However, since it received a second season, I will no doubt watch it.^^
And also to point something important out..
Just because you don't like it doesn't mean it doesn't deserve a second season. There are plenty of series I don't like yet I don't see why not of the idea about a second season as that there are people who are either amused by it or simply like it for a variety of reasons; I don't mean just mecha or ecchi love comedies but other animes are all the same. A number of comedies are plain malice but there are people who get a kick out of it and thus, it gets tons of episodes and multiple seasons. Generally, if the comedies aren't ecchi, its malice. This is what anime and manga is all about. Either get used to it or do something else. Sorry for being harsh but this is the reality of it.
