Quoting these posts from Steve after TTBAB closed:
Tough To Be A Bug isn't coming back. Very much like the situation with Alien/Stitch Encounter, Disney has been looking to exit Tough To Be A Bug for some time. It received a high number of guest complaints, and due to the nature of the show, was a poor utilization of the space. The new show will be far more child friendly.
It isn't very few. It had a comparatively high rate of guest complaints. There were kids crying at almost every single showing. And some of those parents left complaints. Pretty much exactly the same as the Alien Encounter situation.