I may be missing something but surely Task Forces can be as challenging as you want them to be?
Dr Infernus (Fire/NRG Blaster) is fully IO’d out and got all six T4 incarnates, but I did a +4 Kill All ITF last night and had great fun with it. No team wipes or anything but no breeze either. Sure, could’ve sped through it and boasted about how easy it was, but I’d have missed out on an hour of really good fun that way.
I suppose how you define ‘difficult’ is the key to all this. It wasn’t difficult to survive or complete, but killing that many +4 (+3 for incarnates I know but +5s for sidekicks) bosses, EBs, and AVs isn’t a walk in the park either. It was just a nice balance between challenge and fun.
But ultimately, you make it as challenging as you want it to be. Adjust mission levels, debuff yourself, buff foes, make yourself a weaker SO build and use that, whatever you want to do.
Generally I think most people who complain about CoH being too easy don’t actually want to make it more challenging. They just want to tell people how good they are - which is fair enough btw. It is a superhero game after all. 🙂