I agree with you on some level, but seeing Fantasmic at DL and DHS is difficult as well - especially if you have younger children. To see F! at DL you need to wait a minimum of 2 hours to save your spot in the seated area for the first show. To see F! at WDW it also requires showing up very early as well. I am not an expert on F! at WDW (I have seen it twice) but I think arriving 90 minutes early is a standard recommendation.
Illuminations at Epcot is easy to see because they designed it to be viewed all the way around the lagoon. But you also are very far from the show elements. WOC needs to be viewed from closer up like F! and that puts a strain on things.
A friend of mine who has seen WOC before was at DLR last month on a grad night and even though she knows how to do all the right things and did them, they still ended up behind too many people and her kids could not see at all - and were very upset. She contacted Disney after her trip - her complaint was more about how the grad night affected WOC - and a CM called her back and said Disney is aware of and is working on the situation.