Why is counting cards such as bad thing?

I don't berate people. But people do indeed do very foolish things. I was playing just a few days ago, was at third base and on a bit of a roll when I drew 20 off the deal. Guy sitting in the middle of the table had a pair of jacks. So what's he do? Splits them, gets two shitty cards, dealer has 16 and pulls a five for 21. We all lost. That PISSES me off. Why the fuck would you break up the second-best hand? In his case, to lose twice as much money and cost the rest of the table money as well. If the dealer beats us when you don't split face cards, fair enough. But don't hurt yourself and the table to win an extra $5. Idiot.

 

Is making ... let's call them against-the-grain moves ... in blackjack worse for feeling the table against you than routinely betting for folks not to make the point in craps?