Personally I think it's rather pointless to have something with synchronized light patterns that is made to be placed on your HEAD, where you, the person who shelled out the 30 bucks, can't even see it. So then you have people carrying GWTS ears in front of them just so they can watch what it does. If they wanted to utilize this technology, they should have done it with something other than hats, which I think they might be doing for the 60th. However, I agree with bumbershoot. I'm there to watch the actual SHOW, so why the heck would I want to focus on some flashing mouse ears during Fantasmic?
Also they used a bit of deceptive marketing when these first came out, showing the videos of a ton of people with glow ears watching WoC, the whole audience alight with synchronized wonder. Yeah, well that only works when you give every member of the audience a pair for FREE just so you can record it for marketing purposes. The reality is that maybe a small handful of people will actually be wearing the ears at a show, that is, if they're even wearing them and not holding them out in front of themselves so they can see what they paid for.
Also, don't get me started on people who wear these things on rides like Pirates, Mansion, and Small World and don't turn them off.

Originally it was said that there was supposed to be a trigger in rides that sensed the ears and automatically turned them off, but that doesn't seem to be the case. In that respect I'd say it's a good thing that not very many people buy them.