Earlier quoted context omitted.
...because if it's say 98%, you have just thrown away 2% revenue.
Hardly, you have to consider the additional cost of attempting to support that additional 2%; it could very well cost more than it's worth in development time and long term complexity. Of course that's an app specific decision. Every market you specialize for has a cost, short term and long term, so it has to be worth it financially; businesses aren't in the habit of just being nice for no reason.
That's certainly not how I calculate revenue...