FWIW, I'm not "anti-cash", I'm "anti-bad trade".
I've played three ways:
1. "I'm a much thinner, considerably better looking American version of deathinahole. NO CASH EVER!!!!"
2. "Yeah, I'd love to have that player but I need you to pay the salary. What can we do to make it work?"
3. "We have a 1.5m cash limit. I'll need to throw in a salary to make this work."
Option 1 makes it tough to trade if one or both teams are near their cap. Perhaps even impossible to trade.
Option 2 makes it very, very easy to trade. Especially if you don't plan on sticking around.
Option 3 isn't as tough as option 1 but, if you've played the game properly, you don't have useless salary floating around. So you end up moving an extra usable piece.