Same for "high profit margins of offering a software product vs. (for example) doing one-off consulting for a German industrial company". Honestly that's a lesson from all the way back to MSFT.
I'm guessing by "paying market rate for experts", they're referring to the pretty large gap between US and European software salaries (even if you're not looking at the Bay).
When that comes up, there's usually some people who say that Bay area engineers are overpaid, but rather I think everyone else is underpaid and should fight for better compensation in general. Evidently you can afford to pay these salaries as a business.