Other market makers are often moving away from something they've seen but you haven't yet. When whatever that is hits you, the fills you got from the other market maker will look really bad.

Not aware of a market maker that also doesn't take liquidity as well. In fact, it probably would impossible to market make without also taking (you wouldn't be able to provide liquidity if your quotes were in cross with the market).

That said market makers do a lot more making than taking.