Doesn't this just make Protection Paladins far more like Warriors?
No, it just means they can use the same gear. You could feasibly design a system where nothing whatsoever changes in terms of abilities but every class in the game uses the same gear.
Seems like a lazy solution to the itemisation problem. Wouldn't it have made more sense to have created more opportunities for Paladins to get gear?
People complain, just like we do about the ret pala chest that drops in ZA. Prot pala, holy pala, moonkin, resto druid, ret pala, druid tank, enhancement shaman, all gear that's currently only useful for one spec of one class. There is no enhancement mail outside tier sets (i.e. has str) at all in TBC, not a single piece. Moonkins got 6 drops across all tiers of raiding, in comparism there are 62 cloth spell damage drops. Mages iceblock if it goes wrong, warlocks howl of terror, priests primal scream, moonkins are supposed to suck it up and take the hit but you can't do that in cloth. Ask Amberley what prot pala itemisation is like, and the same goes for the other specs I listed with the exception of the healers. Holy palas got 30 drops and resto druids got 31, guess what Blizzard wanted you to do in TBC?
The loot tables are already cluttered, either some specs continue to be stiffed, the loot tables get even bigger than they already are, or the loot is made useful for more than one class. Blizzard have chosen the latter, it even started with a change to feral druid mechnics a few patches back to make rogue gear better for feral DPS. Of course that was the end of strength on leather which meant enhancement shamans were even more stuffed but that's something they fixed in WoTLK (enhancement shamans in WoTLK get AP from agility).
Seems like they are blurring the line between the classes somewhat, and I can see Warriors having serious issues with this since they are now rolling against Paladins even more than they already are, not to mention the fact that Paladins are looking more and more effective at tanking than Warriors these days.
The lines are not blurred in the slightest, if anything WoTLK defines them even more rigidly. Prot palas are AoE tanks, feral druids are melee tanks, DKs are magic tanks, prot warriors are the jack of all trades. Just because you use the same gear doesn't mean you're the same. Like I said, I can design you a system without using tokens where each boss drops 2 generic items that are useable by every class in the game without modifying the end effect of a single ability just changing game mechanics.