I'd have you keep on running the iTrials. Getting rid of them after the fact wouldn't have served anybody's interests.
At the same time, however, I'd like to think that had the devs given us an Incarnate system (which I use to collectively refer to the iTrials as well as the new power system they unlocked) that was consistent with the systems and gameplay of the rest of CoH, more of the subbing CoH community would have eaten it up and enjoyed it even more than what we got. And after all, if you're a big fan of the game and the innumerable ways it was different from all the other MMOs out there, "more like CoH" is axiomatically superior/preferable to "less like CoH", is it not?
It's too late to do anything about it for CoH, but there's still time to influence the future "successors to CoH". I'm hoping the devs of CoT, H&V, and VO will take the opportunity to reevaluate Paragon Studio's approach to end game content and make theirs more, not less, congruent with the rest of their game(s).
That's certainly a fair enough thing to hope for. However, in defense of Paragon Studios, I seem to recall reading something Positron(Matt Miller) said about the incarnate content. They had this code that was undocumented, or poorly written, or had other issues that made changes difficult to implement. I think, if they'd had the chance to raise the cap to 60 or 70, they would have done that. Apparently, for whatever reason, that level cap of 50 was there to stay. (I seriously would love to look at that code and see why - not that I'd be able to make much sense of it unless it were in Java or C++.)
So, they came up with the incarnate system - and probably had it planned out since they created Ouroboros.
You did acknowledge the "rock and a hard place" that the dev team found themselves in, but I never thought of it like that. I looked at it like they had an opportunity to solve a problem - which is what a computer programmer is trained to do. It's all about problem solving. Some solutions are eloquent, others are bloated. Kind of like some of the dialogue we see in the forums here.
Some, like Codewalker, express themselves concisely and clearly. Others, like me, use humongous paragraphs to convey what some could do in a sentence or two.
I'd thought at first I strongly disagreed with you, but it seems you did make a qualifying statement about loving to play the 1-50 content. And, I don't think I did. At least, not the way others did. To me, it was always a means to an end. That end used to be level 50, tackling Dreck solo just to see if I could beat him. But with incarnate content, I got tools which would help my squishies deal with AVs like Dreck. Pets, nukes, buffs, debuffs - all in addition to the primary, secondary and Patron/Epic power pools.
I certainly did not enjoy Keyes, except for the AV fight. In fact, except for the AV fights, the only trials I enjoyed were UGT (because of the number of AVs and the guaranteed rare or very rare component.)MoM and the Magisterium. That last fight against Cole, having to zip in and out of lightning blasts was a real hoot. Probably the most fun I've ever had playing the game, particularly when going for The Really Hard Way.