Re: what about Apple?
Simply because it doesn't hold a dominant position. The day it has, it will incur in fines as well. Maybe that's one reason why Apple is interested only in the upper market - it ensure big profits without incurring into antitrust regulations.
Antitrust law are designed to apply only when the market becomes heavily distorted by entities who are large enough to use their weight to achieve it, especially across different areas - not to to control each and every company, which would hinder innovation and growth.
Be also aware that a dominant position per se is not unlawful - its abuse is.
You may want to use Google to perform some searches about how it works....