Well it's not like Putin gave them a heads up, they kept denying invasion up until the very last moments and even then they announced a freedom mission for the "republics" and instead went full scale across half of Ukraine. So I don't see how it's not a good look to protest now, their gov kept lying to everyone up until recently.
Just to be clear, I have the utmost respect to the protesters in Russia, I just wish there were more of them. Because judging by social media, there're also a lot of pro-war Russians