Bottom line: Star Trek isn't the broad crowd puller that Paramount thinks it is. The franchise stands more chance of success if they don't put it up against movies with much better street cred.
ST:TMP performed well - and had a very broad demographic - because it followed almost a decade of TOS (and TAS) repeats in syndication, and at times when children could watch with their parents: early evening prime time.
It hasn't had the same "crowd puller" value ever since. Certainly, the success of TNG in first-run syndication in Seasons 3-6 (its peak?) had merchandising running high, but it was perhaps all downhill since then - with the latter series screening later and later to fewer and fewer - until Bad Robot revived things in 2009.