I think so for the sole reason that Russia is a nuclear superpower fighting a war of aggression against its smaller neighbor. Any infrastructure supporting the aggressor seems like fair game to me, if the Russians don't like it they can withdraw and they will be fine. On the other hand an aggressor devastating civilian infrastructure to torture the country it is victimizing seems much worse to me. The Ukrainians don't have a choice other than surrender, and they won't be fine if they surrender. Also I don't know anyone has died due to the pipelines being blown up, there have been deaths due to the dam being blown up and likely there will be more.