Maybe the novelty has worn off? It's very nice when you first see it, sitting there with your Ray Charles doo-dads on and watching the fish on your TV swimming around in front of you but after a while it's a little boring and sometimes in the wrong daylight, gives you a headache.
You get companies taking the pee by selling you a 3D TV for £1500 and then asking you to pay another £75 for the glasses! My old man spent the best part of 3 weeks raking over various forums and articles before selecting his 3D TV, he's retired so he's all the time in the world so to speak, the rest of us have jobs, kids and DIY to get sorted out, we don't have time to wade through the guff to get the right one.
I think we're probably waiting for the proper holographic Star Trek type doohickey experience, where you don't need anything extra attachments to get our immersive televisual experience!