We want and need to disseminate our results as much as possible and the paywalls are getting more and more in our way. You won't find many scientists who are against Sci-Hub - maybe a few at some unusually rich universities of some very rich countries that pay $500 for a color graphics and the $2500-$3000 fee per article for them that makes the publication "open access".
Poorer countries cannot afford the journal subscriptions either, because these can be exorbitantly high - so high, that even top universities have to limit access. I stumble almost daily over a journal to which my institute doesn't have access. Before the advent of Sci-Hub, we often had to ask colleagues abroad on mailing lists for (technically illegal!) copies of articles to be able to conduct our research.