The abyssal proving grounds recently only allowed T2/<Meta4 modules to enter (and no special factions ships). This isn’t such a good idea.
Most ships in EvE have their own rock scissors papers game. Therefore, bling ships don’t guarantee winning. On the other hand, being lucky and countering an enemy bling ship is an amazing experience (and profitable). For example, if special edition corvettes are allowed into the corvette proving grounds, it would be an excellent opportunity for 5 people to go on a very blingy kill mail.
What about showing people the death of some bling ships? Instead of banning bling altogether? Say: "Look, these people are losing much more isk than you are, and if you kill them you’re rich. That’s good, right?