I agree with you. Let them shout us out.
It seems to that the focus of the game has moved to clearing +4/x8 mobs as quickly as possible. Relatively few people want to take on intentionally challenging content. I am not sure why this is. Unfortunately, controllers are very useful in the difficult content that doesn't get much attention.
The solution, for me at least, is to build controllers for as much damage as possible. I don't feel useless on my Plant/Storm because I help clear mobs with AoE damage from my pets (Flytrap, Creepers, Tornado, Lightening Storm), as well as confuse enemies and debuff their defense and resistance. I don't lock down mobs entirely; I mitigate enemy damage while contributing a good bit of my own.
The days have passed when a low-damage-high-control Controller is useful. Things are dieing too quickly for an Earth/FF to shine. Don't fight the trend. Join it and build an offensive controller.
I was on a small team last night. I have a feeling a lot of leveling post DFB's will be that way as well unless you are doing TFs. I think the days of one sided builds are done in terms of being useful. Sadly, I recently made an Ice/rad controller as I always wanted one back on live. I don't think controllers are useless on teams. There is still annoying content, ie Tsoo, CoT, etc. I just think you can get a lot more use out of builds which have a bit of diversity to them. See also me thinking why tanks are going to be to harder to come by as brutes on smaller teams can work perfectly fine. Been itching to do a Fire/rad, and I might just reroll the Ice/rad into it. Granted, I already have an Ill/rad so that's partly why I keep holding off.
FYI, I have soloed a lot since coming back. Most normal teams I have been on don't get filled. The team last night was three people until we looked for some support. We were scrapper, blaster, and tank to start. A controller would have been useful there. We added a defender. Hell, if I get the chance to team with a friend, my default is grabbing a controller as he seems to love sentinels.