Sure we gain experience but with a whole wardrobe of heirlooms what does it even matter. Now that enchants scale with level, in which blizzard decided pre-60 to just say fuck it and stick with a static # based on a level 60 character, players are even more overpowered then ever at low levels(I like the idea of scaled enchants but not in their decision to just not give a shit about anything pre-60).
I enjoy playing in the high level and low level PvP brackets for different reasons. I enjoy the complexity(to a certain extent, it has gotten a little out of hand) of max level PvP as it is a good way to become familiar with all of your abilities if you are interested in succeeding. Low level PvP gives me that vanilla feeling where I barely had any abilities and had to maximize what I had.
It takes me approximately 30 minutes(depends on starting zone) to get a character to level 10 with full heirlooms and bracer,glove & boot enchants(usually haste). I can level through this entire bracket facing a combination of trial accounts(limited gear), normal accounts with some heirlooms or people fully twinked out over the course of a day.
Generally games in the 10-14 are pretty exciting and pretty quick because both sides usually have a handful of each of the above mentioned gear variances. Sure some matches are completely lopsided but many of the twinks in these brackets switch between horde and alliance. Personally there is nothing fun about GY camping the other team in Warsong or AB, I want to at least feel like there was some kind of challenge.
So I gain experience, reach level 15, now I'm in a new bracket. Usually I keep PvPing until I reach 20-30 and then I fire up a new class and start all over because it only takes me 30 minutes of grinding mobs which I'm usually 1-2 shotting depending on the class. Unless it's that BG's weekend I can stay in the 10-14 bracket usually all day unless we win every single game, which doesn't happen very often.
It really feels like chess when you get a balanced battleground because you have your pawns(trial accounts), knights and bishops(couple of heirlooms), rooks(full heirloom w/o enchants), & Queens(fully enchanted).
Of course there are people who just want to run around 1 shotting trial accounts for some kind of ego boost and that sucks but if both sides have a relatively balanced combination of the above roles then that changes the pace entirely. I've seen many trial accounts adapt to the fact that they can't do a ton of damage and instead start maximizing their other abilities(albeit limited) while weaving in damage which is huge especially when taking down a healer.
I've had many thrilling matches twinking the 10-14,15-19 and 20-24 brackets with even the lowest gear players doing what they can to hold their weight. I personally find that more players utilize team work more effectively in this bracket because leveling or playing it is a choice and everything you gain from this choice you can gain much more in another avenue(Questing/Dungeons).
Did I mention that there are pretty much no bots either which is awesome!
My Partner does vegan food art @Monaco's Kitchen:
As for there's no challenge in it. maybe before XP off brackets, but geared twink vs geared twink in XP off brackets? Try a few 70's XP off battlegrounds then pass judgement of how it is now, rather how it was when you were in levelling BG's.