I would assert that the exact opposite is true. Taking a strong stand in favor of users would increase their market share.

Over a decade ago, one of the best things that Firefox did to compete against IE6 was to include a built in popup blocker that was on by default. Exactly the same criticisms were made.

It was called irresponsible and disruptive, since so much revenue came from popups, and horrible flash-based full screen pop-under ads. But I am glad that Firefox didn't let the pleas of the established market prevent them from siding with users.