I know that it's not statistically sound, but as an informal straw poll I don't know why people are so eager to put this down. "Kind of tired", "don't trust them", "mostly fantasy" - these seem like oddly agressive phrases to me which probably reflect personal anguish rather than a desire to see the facts.
If we take the $300K+ figure as an outlier, what I see are pretty much peaks at around where I get LinkedIn spam telling me I can make $x. [Edit: to clarify, by "peak", I am referring to peaks if you were to plot the responses in a histogram, not a dollar amount.] I'm going to guess which peak someone is likely to fall in varies with factors like years of experience, when you entered the workforce, how often you changed jobs, luck or whatever. Then I see a significant amount making more and a significant amount making less. I don't think that's all that unbelievable. I don't think it makes sense to overemphasize that the poll is informal and not scientific - the poll still tells you something, even if not really that much, so why dismiss the messenger?
This reminds me of when I lived in Seattle, worked for MSFT and used to read "Mini Microsoft" threads around bonus/promo time. People would post level/base/bonus and how they were evaluated. That too was unscientific, but the company was pretty standardized around titles and how well you could do at bonus time, so it didn't take much to figure out that most of the data was probably accurate - and seeing that, even if it was totally unscientific, served as a reminder of how the place worked and where you fit into it. But then you got a lot of commenters who I think were bitter, jealous, or in denial that it was possible that the guy down the hall was doing better than them. So in a reactionary fashion, they start attacking the other posters, calling them liars, non-employees, whatever.