The problem is most people don’t understand that SX OS has multiple features that others, including Atmosphere, don’t have. Emunand, XCI loader and HDD support are examples. Yes, Atmosphere supports 7.x and yes, SciresM is definitely the best developer out there. But keep in mind that Atmosphere is a "basic" CFW — not saying it's bad, just an observation.
Is it a shame that SX OS hasn’t been updated for 7.x yet? Yes and no. The worst part is that they give no ETA at all, not even an update of their current work. But as of right now, 7.x is not a requirement at all so let’s not pretend that everyone has to switch to Atmosphere suddenly.