Right now I've been leveling as monk and around level 34 I get 3k experience per victory and nothing per loss. With 220k to level up the 3k per win would take a while. Now I don't think that these pvp matches should give experience like fate grinding or doing the main story quests should, but perhaps it should at least be more comparible to grinding mob kills for experience (since you're doing lots of pvp matches). Just numbers for example I feel like 2k experience for a loss match and 5-8k experience or so for a win would be more reasonable.
Not ridiculous, but assuming you win 50% of the time, 10 games would net you around 20-40k experience, which is a decent chunk of an experience pool. These are obviously just example numbers that I believe would NOT be more than fates but still some XP reward for the time you invest. It would probably increase the population of the pvp scene as well.