The argument against using Chromium has increased significantly with that move.

Before you could argue that the open source Chromium was largely immune to Google's various small bad behaviours, but when they make such a large close-minded move, at a certain point you can't keep supporting the platform as a whole when they are so hostile to the open internet. Even if it's indirect support.

Also, it can't be ignore that Firefox's recent move towards parity with Chrome has played a big role in giving people the option to even switch.