Just my take but Buzz and Stax flaming Sylvan is probably coming from the fact that they've seen themselves in Sylvan's situation back in their DRX days. I've seen quite a few times where Buzz or Stax have had stinkers or "threw rounds" because they could not win their 1v1s.
I know this is probably just some crazy trolling, but there wasn't a mil on the line during the time of the documentary. It was basically all blowing up in the group stages where the stakes are not even that high. T1 was 3-0 until they lost to RRQ and Talon. T1 basically guaranteed themselves a playoff spot with their first 3 wins. Sure it would have been nice to have first seed, but you can easily turn things around if you have the right mentality and take the appropriate steps to really improve yourself - just like how PRX did.
When everything was on the line at Bangkok, everyone but Buzz was popping off in Map 4. In those high stakes situations, you cannot be focused on blaming others for the past because Buzz improved for Map 5. You can feel everything in the aftermath, but you cannot be distracted by your emotions when you are still in for a chance to win no matter how small it is. That's the difference between playing ranked and playing professional. T1 were so distracted by blaming others midgame and midseries that it destroyed their synergy. Maybe it was the high expectations that they held themselves to after winning Masters, but you need to provide constructive advice that is more down to the tactical decisions rather than "Did you even shoot your gun?"