I don't think zoos spend nearly as much money on these things on the whole as people think. A lot of them are coming from the same traveling shows/exhibitions and models being reused to save costs. They are probably paying a licensing free rather than a construction fee. For some zoos this is probably much less money than the cost of a new animal exhibit and upkeep and probably brings in a good number of visitors who wouldn't otherwise come who can contribute money towards the actual animal exhibits.
I can tell you the DINOSAURS ALIVE exhibits at Brookfield Zoo tended to lack frilled Dilophosaurs and not only included feathered dromaesaurs but even feathered ornithomimids which even ameteur paleontologists and paleonerds are prone to neglecting. I doubt anyone on zoochat would have felt much preferable to it, because it's still animatronic dinosaurs, but it was certainly better than scaly monsters. ICE AGE GIANTS was similarly fairly realistic and very charming.
Sometimes inaccurate depictions can still stimulate the imagination and education -- as a child I was perfectly capable of watching outdated films from the sixties with sluggish stop-motion dinosaurs and still reading modern books about the animals and understanding there was a difference between entertainment and education. A lot of times if I watch any movie that has a historical element, I immediately look up the real historical figures involved to find depth. I definitely don't think most people go to that last degree, but it's not as uncommon as I think some zoochatters are assuming here. I certainly don't know many kids whose interest in dinosaurs began with skeletals and reconstructions.
I don't think we need to drag toys into this, which is an entirely different question... the toy industry is not known for scientific accuracy with some of their depictions of living, breathing animals and even actual human beings. There's plenty of zoos that sell White tiger toys and some that sell dragons and unicorns. The money still goes towards the zoo.