I hear that there are a lot of bots that are on Splinterlands - they could be pushing up the transaction rates too.

The bots are a mixed blessing. They do provide liquidity (and each account must have "purchased" a spell book and put money into the game). They also provide enough "players" so when you are looking for a match to play you can normally get one quickly. However it does take away a lot of the games-man-ship and fun from pitting your wits against anothers.