Upkeep was and still is a fail, fast-tought and brutal solution to a very subtle problem.
As you can never hope to go any further than level 35, heavy armor and expensive equipment is not optimal, with or without upkeep.
The "tincan" problem we had before the january patch was that people could and actually were level 40 and more. At those levels you can wear plate without any problem. Currently, with all the characters at level 30 or a little over, light armors prevail in combat against heavy armors, which only are good for first line shocktroopers. If big melee clusterfucks don't happen, then heavy armors are pure gimp. Weight slows down people so much that it is actually safer to wear light armors to protect yourself against projectiles. An decent archer or crossbowman hardly ever misses a plate guy at 200 meters. The same person with peasant clothes is way harder to hit.
This is about armors. The case of horses is different. Pre-january patch, horses were rare because many people didn't had the patience of accumulating so much money. And by the end, peasant plate chargers, The Finn and copycats were proofs that it needed some tweaks. Upkeep "solved" this by essentially making any decent horse an unsustainable goldsink, except for extraordinary good players. I don't think there are more than a handful of courser (or a more expensive horse) users that break even without switching often, so it is sort of overkill, and not enough at the same time.
Not enough simply because upkeep doesn't force you to use sustainable gear. If you have 1M gold, you can afford black armor + plate charger during several hundred rounds, if not more, so trolling is still possible and actually happens (no I'm not looking at you skyrayfox). This also means that people do grind. The reasons for grind didn't disappeared, it's actually the contrary. As the battlefield became increasingly competitive, even one heirloom point can make the difference between killing and dying. So now there are two reasons why you would grind, to get gold, and to get heirlooms (which in the end is the same thing with the marketplace).
Joker did an extremely well documented suggestion, describing the flaws of upkeep and how to design a system that could achieve the same goals without ruining equipment weight diversity, the feel of progression and the class balance. But as always it got trolled to the bones, just like any of his interesting posts, mind you, that wasn't really surprising.
And about "skill allows you to wear better equipment", this is just a big myth. First, your income and expenses are extremely random. Second, expensive doesn't mean better. Third, you will be teamswitched much more often if you have a good k/d, and that usually means losing your multiplier. And finally, choosing your banner wisely well will help you ten times more than playing well. Try changing your banner to T, DRZ or STR and join the russian server. Watch the xp and gold flow in like never before.