Why the fuck would somebody stay with a broker after 2 serious execution errors?! If you aren't trading international markets, there is absolutely no reason to stay with IB.
Simple, their API. When you write a lot of code specifically for their API, you're somewhat stuck with them as re-doing all the work will take months.
Also I'm international and most US brokers are not as friendly towards us.
There is still a lot I like about IB, their platform (when it works) is great for me as are their tools. But since I pay quite a lot in commissions, I also expect decent execution - hung orders and mis-executions are a big no-no.