Not presently, but a less creatively secure version of myself absolutely did. During my development as a gamer and a GM there have been a number of people on this particular board, elsewhere online, and in meat space have said and done things that made me feel unwelcome in this hobby. I'm 36 right now. I was like 14 when I started posting on Eric Noah's message boards. Several posters are still posting in this thread. There are times where I have felt like my discontent with mainstream play meant there must be something wrong with me or like that I was in the wrong hobby.
Posters like
@Imaro ,
@Bedrockgames (although in other spaces) and
@Ovinomancer definitely contributed to that experience for me back then. For awhile they became like my Detroit Pistons. This was especially true in the 4e era where I was still finding my footing as a GM. I used every time someone would say that I was basically irrelevant, that I just did not have experience with good GMs, or that I was not really playing a roleplaying game as motivation. I developed a Michael Jordan size chip on my shoulder.
I feel like I have gotten to a place where I do not have as much of a chip on my shoulder and can address this stuff in more reasoned ways, but I probably still have a bit of a chip on my shoulders. As a pretty competitive person and a lifelong athlete I tend to use motivation where I can get it. I think I'm older, somewhat wiser, and definitely more experienced now. Things have a lot less stakes (to me) now because I have gotten to experience what I was looking for and not finding when I was younger.
For one I am a lot more open to more mainstream games now to the point where some of my favorite games like Pathfinder 2, Exalted 3e, Vampire 5e, Legend of the Five Rings 5e and Worlds Without Number are fairly mainstream in approach.
The living world stuff is a bit of a cultural thing for me, largely because I have heard overly romantic depictions of it sold to me for years when I was struggling as a young GM. They made it sound so easy, like it just happens naturally. There was no road map. No procedures. Just throw yourself to the fire repeatedly. It led to years of frustration for me personally.
I also really do think it's impossible to actually do. I think it's pursuit is valuable. There are all sorts of impossible that are valuable to pursue. However, I think it's really frustrating when you are someone trying to do it and not getting there when people act like they are routinely achieving the impossible. You can feel like an imposter even when the people you are playing with are really enjoying themselves. I spent years feeling like I could not measure up because it seemed like everyone was doing what I could not until I realized they weren't actually doing it.