Yes, you're right, I suppose fighting even con mobs for badges is actually still quite easy. Maybe it's even more fun. It's probably even still safe, just less fast. Then again, badges should be earned, I suppose, so a little more effort probably would be not a big deal.
This is not the solution to the problem I want to solve. If a lower level char is the team lead, they will still rise to the level cap in a very short period of time, and hence make it time to leave the hazard zone, hence defeating the goal of revitalizing the hazard zones by making it attractive to spend more time in them. Yes, you could maybe have the team lead disable xp, but that's still not a solution. The goal is for everyone, team leader and the entire team, get great xp.
I seem to recall the principle behind the hazard zones was - greater risk, greater reward. Well, they don't provide greater reward anymore, and they don't feel particularly risky - I'm not sure why but maybe because we level up so fast. What I'm looking for is a way to bring them back to greater risk, greater reward. I think being able to set it such that you see permanent +4s (or higher), and also perhaps maybe making spawns even bigger and more dense, might do the trick.
This is kind of my point (HC vs live), you don't see these kinds of things on Homecoming because XP/inf/merits/incarnate stuff is basically quite easy to acquire, so it's not worth the effort to do anything that's slightly exploitative or abusive. Live was different, without double xp, AE probably(?) not as rewarding, markets that automatically transform enhancements from any level to any level and even attune them for you, etc - you had more incentive to try to take shortcuts. But also as I said, it's fairly easily avoided by enforcing either a 5s delay after changing, being unable to change while in combat, or only allowing change while in a rest state, or only allowing change at some NPC at the entry to the zone, or any other similar fairly easy adjustments. It's more of a question of which is better big picture. I still would argue for making it an opt-in, and more particularly being able to set your level below the level cap so you can see +4s (or higher).