I think because it's the first season of the expansion the alt gearing problem seems worse. A lot of people are still levelling alts and just aren't putting as much time into arena because of all the other stuff that's going on.
Regarding offspec's and latecomers, imo they should start from the bottom like everyone else. It's not too late for latecomers to get caught up, especially if the team has a decent rating.
The problem with the current system is it rewards you strictly off of how much you play and how early you started playing, and skill to a very small degree as you get a higher cap as you progress. Latecomers will always be guaranteed to be however many weeks behind and it's annoying.
I leveled my pally first and then decided I didn't like Blizz's changes to Shockadin at 90 so I leveled my mage up. Now since I didn't level my mage first and she was 2 weeks behind on getting conquest points I can never catch players who decided to PvP with their first toon gear wise. I'd be perfectly fine with this if gear didn't play the insanely huge role that it does in PvP. Unfortunately, especially with the introduction of PvP Power, even having a few less pieces, or a few pieces that are a tier under your opponent puts you at a huge disadvantage.
I completely agree they should start from the bottom, welfare epics are one of my most hated features in the game, but I don't like that you're forced to start at the bottom and no matter how good you are, no matter how much effort you put in, no matter what you do you can never overcome those players who all they did was start playing a couple weeks earlier than you did.
Yes you can raise your cap by getting a higher rating, this is meant to be between players of approximately the same skill/rating.
Mate, don't even try to tell us you're stuck at a certain rating because 1-2 slots of your character are a few item levels behind someone else.
In fact, it's exactly that kind of attitude that will forever ensure you stay at those ratings, because you refuse to take personal responsibility and learn to overcome whatever is plaguing you in the matches...and believe me, it isn't because your character is avg ilvl 458 and someone else is 460.