How many people do you require for it to be a legitmate concern? I can show you millions but you will disregard them anyway, because they all have wrong opinions.
I don't know where to draw the line entirely, it probably depends on a mixture of absolute numbers, relative numbers to the population involved in the discussion and the issue discussed. But it's clear that in this AI discussion case, telling "suck it up" to all the people complaining it's rude.