Why would google not promote its own services first and foremost? Why would they not use their market dominance to squash competition? That's how capitalism works. To not use their position to further advance their products would be ignorant.
> Why would google not promote its own services first and foremost?
Same reason why it was wrong for Microsoft to put Internet Explorer and later Windows Media Player in Windows: It is anti-competitive for a monopoly to utilise its market position to gain an edge into other market.
> further advance their products would be ignorant
I think you meant "foolish." The word "Ignorant" doesn't work in that context.
Ignorant:
1) lacking knowledge or awareness in general; uneducated or unsophisticated
2) lacking knowledge, information, or awareness about something in particular
With the notable exception of Google+ (which has now been relaxed), signing up for one google service did not force you into any other google service or product. You can access any google property on IE or other browsers. There is no anti-competitive compulsion in the way that Microsoft forces IE upon windows customers.
Semantics aside, my point is why would you not attempt to gain every bit of leverage that you can. There are no indications here that google is breaking any antitrust laws.
Sure, antitrust laws exist, but you don't handicap yourself before you're even breaking the law. And if you are breaking the law, then it is the justice system's job to stop you and that is who we ought to be upset with.