The complaint from MS is not really that “Bing” shouldn’t be a gatekeeper, but that Windows (which is the gatekeeper) should be able to give unfair advantages to “Bing” (or any “small” product they want)…

Microsoft is “unlikely” to dispute that its Windows platform meets the definition of a gatekeeper, but it’s arguing that Bing’s relatively small share of the search market (compared to far more popular competitor Google) could only be further diminished if it must do things like offer users access to rival search engines.

Windows being a “gatekeeper” is independent on how successful they are in their attempts to exploit their gatekeeping power.

Just because Bing is so unpopular that people don’t use it even after slapping it in every possible MS product, does not justify exploiting Microsoft’s success in a completely different market (the OS) as a means to give unfair advantages to one “small” product over the competition.

Windows, as a highly successful & popular product (almost a monopoly), should not be forcing ANY alternatively monetized Microsoft product (regardless of their success) down its users throats. Windows should make business on the basis of it being sold as an OS, which is what they are advertising the product as (and it’s already successful enough at that). Not make business using their powerful position to give advantages to alternative Microsoft products from other markets (eg. unfair gatekeeping).

If Microsoft is not happy with those restrictions, they are welcome to surrender that position of power and stop distributing Windows in the EU. I’m sure there are many competing alternative Linux distributions / organizations that would be happy to comply with the EU regulations if they were the ones replacing Windows as the new popular gatekeepers.

And the same should go for Apple with iOS/Mac or Google with Android.