Ultimately, Google is stupid for this, and they hurt their own bottom dollar.
Think of it this way, even if only 20% of YouTube consumers are driven even mostly away by Google's actions, that's 20% reduced advertiser reach. So the "big tent" advertisers now have to cut funds in order to reach that 20%, or find a new venue that reaches the whole 100% of their consumers. What Google will be left with is the short reach and niche products as their backbone- which isn't all that true, the large reach advertisers will still be their financial backbone, but the smaller brands will now have a larger voice, driving more consumers away with their SJW demands.
I guess the TL;DR of this is that this is just one more step for Google becoming one option of many by reducing their competitive edge. With the Google leadership being so SJW, they probably won't realize their mistake until it's too late to dominate the market.