In metal screaming i hear all the time that you only want to drink water, but i see alot drinking pop, help?

Okay, so i always hear that water is the best but i just found the most insane screamer ive ever heard named Jake Terrell from Project Fight the Sky, and his drinking consists of pop and beer and the like... So can someone please break this mystery for me..?

Water isn't cool enough to drink in public!