This might be off topic, but I thought I'd throw my thoughts in here anyway.
Isn't that how it is right now? Mechanics have been shunned, unless it's a heavily trap infested quest, since I started playing. Before Update 9 playing a pure rogue acrobat, I could hear the disappointment in people's voices when I told them so..and usually got lectures that I should either be an Assassin or respec with Monk levels if I wanted to be useful. Seeing the writing on the wall before the update, I TRed to gain some past life feats since the last Update made the gulf between Assassins and other rogues extremely huge.
And rarely do you find PUGs that allow more than rogue. And it's near impossible to get people to join LFM for a regular quest if there's two rogues. Heck, I've seen groups drop rogues altogether if there was a multi-class that splashed rogues.
One of the things that would help rogues with 100% fort is if the Precision feat would remove the halving of sneak attack damage (and treated like elemental damage with the feat). With this adjustment to Precision feat and the Opportunist feat, rogues would have the 35% bypass without penalty. It would cost a precious feat spot... but the adjustment would be a "give" to sneak attack since the lack extra helpless damage was a "take" from sneak attack.
....Getting to the raid ideas...
I agree that Rogues would be more of an utility role, at least if there's a fight with a 100% fort Boss. By Utility, I don't mean traps because that would still mean the wiz 18/rogue 2 would knock all other rogues out of the group with many, many groups. I'm talking more like trash patrol, such as the Orthons in ToD part 3 or mephits in SoS. Also there's back up heals and rezzes for the UMD rogues.
Another Utility role would be to hit random runes during the fight. Runes could randomly light up in the room and must be turned off to prevent something from happening. What could the runes do? Spawn portals or open doors that allow trash to enter. Maybe the runes make the boss regenerate health, attack faster or hit harder.
These are just a few ideas that could be implemented that would allow any class to participate, but wouldn't prevent rogues or bards or any other "not flavor of the month" class/build from joining.