What if you set up a booth in a shopping mall in the spring of 2016 in California or Massachusetts and gave away pro-Trump stickers? I assure you there are plenty of people out there in both states, many of them likely working on YouTube, who view that as equivalent to your hypothetical. I know a number of them personally.
Trust me, I'm not a fan of the sort of rhetoric you describe. But I also don't like slippery slopes with no guardrails. I expect we'll end up with guardrails here in the end, after a few decades and a bunch of court cases, but it's going to take a while.
Now very likely Youtube plans to do extremely selective enforcement. I'm not sure that over-broad rules with ensuing very selective enforcement, applied only against the powerless and unpopular, is the right direction to head in, but that's what I see going on here.
I think the truth is that big platforms that are conceivably open to anyone eventually become abused, unevenly enforced, and end up being a gamble when it comes to business. YouTube, Google play, Apple's app store and many more are all examples of this.
Also, I couldn't care less whether things are a gamble when it comes to business. I do care about public discourse and control thereof.