That's a 50 DKP minus right there.
The endgame of CoH, on Homecoming and the old game both, is 'roll an alt'. If you really want difficulty, there's always levelling through the Positrons and Synapse. Those things are as difficult as you seem to want to make the whole game. There's always Praetoria, with its missions full of Seers. There's always Night Ward, with mobs stacking unresisted mez.
'Adding difficulty' eventually makes characters and classes irrelevant. I run Malta and Carnie missions on my /electric armor brute, who laughs at Sappers. But if you do those arcs expect to do them solo. I would not take the character on an Apex TF, where a Brute is basically AFK through the whole Battle Maiden fight. Adding difficulty seems to involve generic MMO crap like 'don't stand here' zones, the sort of garbage that sends team leaders to immersion breaking VOIP chat to manage the choreography and cat-herding the raids require. I love CoH more than any other MMORPG because that kind of twaddle is mostly absent here. Adding more of that is pretty much the definition of unwanted change.
And the player base doesn't seem to want it either. AE farming is ever-popular. Praetoria is a ghost town, and redside generally is too. The Incarnate trials that get run more than others are BAF, and to a lesser extent, Lambda. They are popular because they are relatively easy. I don't really see an outcry for more difficult missions or mobs. More difficult content is already in game, and already unpopular because it is more difficult. The OP's position is a minority one that the behavior of the silent majority of the player base rejects.