They should have done nothing.
Completely agree, and it's what makes me more angry than anything else related to the mess that is Firefox today.
They utterly discarded their core user base, the people who loved and brought the browser to the point it was, chasing some pipe dream of market share percentage points. They became convinced that trying to maintain that share was more important than anything else, and so, like an anorexic person, went on a self-destructive rampage trying to achieve that impossible and truly undesirable goal.
Firefox should have let Chrome cater to simpletons, if that's the direction Google wanted to go. We now have four(ish) primary browsers -- Chrome, Firefox, Safari, and IE/Edge -- all of which seem to be made for the clueless. All the edges have been sanded down, extra buttons and knobs removed, and privacy only an afterthought. Instead of a bright standout in that lineup, Firefox is just another loser, trying to blend in with the "cool kids".