For one because Google's Android does not qualify as a monopoly and the mere existence of Apple's iOS which has 20% of the European market is testament to that. But also because having a monopoly isn't illegal and I'm quite curious what anti-trust charges they are going to bring, because as the parent says, Android has been the most flexible mainstream mobile OS, more than iOS or Windows Phone. Android is the only one on top of which Firefox was possible, the only one admitting third-party installation sources and app stores and the only one that can have a CyanogenMod. Android is actually the only one that can be forked and Amazon has successfully forked Android.
And the reason for why it doesn't make sense is because Google charges no licence money for Android and they've been quite forthcoming about the reason why Android exists, right from the start, its existence being all about Google having a mobile platform to distribute their apps and services. Phone makers don't even have to agree to this, though no Google agreement means no Google Play, terms that again, have been there from the start. And in fact Apple and Microsoft have both used their existing position in desktop operating systems, an easily provable oligarchy, to push their mobile OSs and lock users in.
> European companies have also brought before court for the same reasons
Oh, come on, you know that ain't true. They are targeting Google specifically because they don't want to share their Search & News revenue with a dying mass-media industry. And I'm saying this as an European.