ST has ben off TV for what 8 years?
Prior to that it was off TV (live action) for 18 or so years.
ST will no doubt return to TV at some point, in some ways the longer it is off the better.
As it would make it's return to TV an event instead of what was happening with VOY and ENT and to a lesser extent DSN. Where some of the audiance might be thinking another Trek show (not in a good way).
Not a direct analogy I know(and other factors have to be considered), but DW the other big TV franchise went off air for virtually 16 years (aside from 1 TV Movie), it now takes pride of place on the BBC's Saturday line-up when it airs.
Remember TV execs come and go, maybe the current crop aren' too keen on doing a new ST show, but in a few years time they might be gone, and replaced by those who grew up on the likes of TNG and want to do another one.