One of the frustrating things about being an anime fan is the reality that like all forms of entertainment, anime is a business first and foremost. The profitability of a series not only plays into the likelihood of a sequel, but of the overall well being of the company that made it, or even the fate of certain anime genres as a whole.
Ecchi isn’t for everyone. It truly does require a different mentality. Sure, there are a few ecchi series out there that work as comedy, and a few others that even work as storytellers. But for most ecchi series, the “plot” is really a thinly veiled mechanism for the writer to manipulate things in such a way that it sets up his next cheesecake display.