People, like me, who never want to play off destinies again, can still do multiple ETRs if we want, but we can level in the destinies we enjoy.
People who still want to switch destinies often or run each destiny with a better paired heroic class can do so. There would be no impediment to that.
I'm not suggesting that people must level the way I want to. I don't think anyone here has. The people lined up against the karma system, in general, have already been there and done that with off destinies and are fighting against forcing people to do that which is unfun. This is the complete opposite of the picture you are trying to paint of them.
BL: removing karma and using level cap as the requirement to ETR will add options for everyone.