Bullshit. How do you figure? You are always free to negotiate yourself above and beyond what your union sets for everybody. I negotiate my salary myself on union jobs ALL THE TIME, and haven't worked for the union minimum in a long long time.
But in E-Sports, the 150K figure is for the very best. The very best are making less than a bench warmer in the NFL. Being the very best means practicing in your team house for 10-12 hours per day. Many top Starcraft players have needed surgery for RSI injuries.So even if you're the best in the world, you're going to get 10 years at best. You think 150K a year is a lot, but after your career is over what do you do? What skills do you have? All you can do is play a video game. You're hostage to it. Former top players have gone on to become coaches, and this is the only real progression left. If you are near the middle or bottom of the pack, your situation is even worse since you have less money.
This is not a long term career like traditional professional sports is.