They were common, just not as visible. If you knew which mailing lists to be on, you saw all the same stuff.
I think the negative contribution from Github is the "gamification" of development. Stars, in particular, are emblematic of this problem, as it grants a measure of "apparent quality" yet it's not safeguarded in any way at all so now it just measures "apparent popularity."
The mechanisms you have to employ to be popular are almost diametrically opposed to those you have to do to write quality code.