This is a really interesting article!

A weighted mean of the number of views and number of comments might end up being just fine for your purposes, but sure, it's definitely a little bit crude. Have you thought about adding a normalization step before averaging the two? Since you're dealing with engagement metrics, I bet your dataset is going to be heavily right-skewed anyway, so applying a power transform followed by a min-max normalization would help with that aspect as well.