Hi, random passerby here.
I was in the same boat for a little bit. People don't tend to just leave guilds they've been in for years willy nilly. I'm unsure of the other person's specifics, but for myself raiding with those people i'd grown fond of is half the fun.
I know not everyone here will operate like that. Some people value the experience, some value only the end result, and both of those things are valid.
It does leave me wondering what both sides consider stressful though. I literally walk in the door and sit at my computer still in scrubs on one of the raid days, but I generally don't feel stressed, just aware that i'm pressed on time. If I was still a teenager I can see how it may seem stressful though. I'm hoping the other poster was looking for the word worried instead of stressed, as the latter is a much broader spectrum of anxiety.
Just attempting to shed some light