For instance, a whole city rioting to break new looms because it was putting "honest weavers" out of business.
Or the publishing world rioting against anything that smells of sharing ... since forever.
Google surprisingly doesn't act like an incumbent at all. And that's good. We shouldn't hate on them because they are incumbents since they're doing a damn good job at it.
edit: Also the whole idea that "When a market is dominated by a single player. That market is ripe for disruption."
And your examples of losing email or Adsense accounts isn't so solid. Those are really edge cases and its a problem endemic to creating applications that need to catch abuse especially when the user base is so enormous. We know computers aren't people and they can't exactly think so considering the amount of data Google has to filter through and knowing you'll never write code that's one-size-fits all I think they're doing a good job. I'd presume any competitor would have similar problems once they grow to a certain size.
I expect someone to call me out for saying you can never write one-size-fits-all code -- to them I'd say it's true; as long as humans continue to be fallible then so will the systems we create. There will always be an edge case and it'll take every last one to pop up before we can even conceive of trying to catch them all. But that's off track so I'll end it here.
As for the 'who' ... doesn't really matter whether it's Google or someone else that fixes whatever problems but historically it's not in their DNA to care about individual users so it feels quite natural to assume they'd be replaced rather than repaired.