The opposite is actually true. There is nothing stopping someone from making a bunch of transactions to themselves, all from (and to) addresses they control. They could even not include TX fees to make this kind of manipulation not cost anything.

The price on the other hand requires real money to be risked in order to move the price in a certain direction.

NOTE: I am not saying that the TX/day figure is being manipulated, just that it would be very possible to manipulate