I won't deny it. But here are my stats and the average type of players I go against (sometimes I go up against players over lvl 250 with Ego bigger than mine). All of them netted me between 1 and 3 Mojo respectively. I played on the clock every 30 min (it's a good break time and brain reset tool for me in my line of work). My total Mojo is 12379 if this matters. The bump in the road was hit somewhere at around 12200. I tried to look at the stats and compare them with mine, but yeah, maybe I don't get what I'm supposed to get. :)) I'm at only 395 PVP wins so far, but out of 10 battles I may lose only 1 or 2.
EDIT: For the opponents after those in the pic below, I finally got 12 Mojo from one and 5 from another. I almost shed a tear... It was like seeing a rare girl drop in the pachinko instead of a story one.
On my list, in the top 10 there are players who are over lvl 260, three over 290, while the top 100 players is filled mostly with people under lvl 200.
I don't find it fair to keep going down the list when I'm winning the big majority of my battles.
Then again, there's one thing I can think about which probably all of us omitted. I'm talking about the possibility that the Arena system right now may be intended by the Devs to work as a booster for the low levels? I mean, it doesn't give Kobans as a reward and while the 2.5 mil and the 5 mil prizes are eye catching, it's not something the high levels with full story explored and all if not most girls added to their harems can't gather in the span of a few days, right?