Okay google, what's the proportion of windows to windmills?

The key is that it's not random at all. Sort of like if you posted a survey on your facebook page, or asked college students at a sports game. There are several layers of bias, and the end result is that you don't really learn anything.

In the first case, you learn what 'your friends' 'who use facebook' and 'who will open the survey and fill it out' think. That's at least 3 layers of selection bias.

In the second case you learn what 'college students' 'at that university' 'who would go to a sports game' and also 'be willing to respond to the survey' think. Also at least 3 layers of selection bias.

If you asked "are sports entertaining?" In your survey, it's pretty obvious the group at the sporting event would have substantial deviation compared to the general population. But those kinds of group deviations can be more subtle or less blatantly predictable as well.

In this case, if this is the only place he's posted this, the survey group is going to be primarily 'redditors' 'with r/internetisbeautiful as a sub' 'who found this interesting enough to click it and fill it out' and so on down the line with a variety of other layers of selection bias. Even if the only flayer of selection was 'redditors' you would find a tremendous deviation from the general population in a wide variety of things.

Not sure what purpose this is trying to fulfill. It's not really gathering any useful data, since the responses are just whoever is sent the website and decides to respond. It's essentially a useless survey group as it doesn't represent anything meaningful.