I commend Jack Dorsey for his ethics. I think there could have been a better solution though - why not just disallow targeting on political ads? Only allow coarse-grained targeting, say at a state level. You still give political campaigns the opportunity to leverage the network and spread the word, and you get at least part of the revenue.

The problem with social media advertising is the targeted nature of ads. If you take that out, and place ads like DuckDuckGo does, it is not that different from newspaper ads and much less dangerous.