A letter from four people "urging" something isn't blatant censorship. Blatant censorship just happens--there's no asking in between (see China for more).

Google is making a strategic decision. Despite what you may hope, free speech isn't YouTube's main priority--it's profit. Right now they're trying to minimize the possibility profits may be impacted by stakeholder action. They don't care if your particular political views aren't adequately represented. Free speech isn't a mandated requirement for corporations.