Apple loves photographers (well, they love that photography is one of the cornerstones of iPhone's success, and what company doesn't love success). The iPhone is one of the most successful cameras ever, and they do plenty to cater to amateur photographers. They love it when their cameras are used to take great photos - they've built entire advertising initiatives behind that. But does loving (the business provided by) the most-practiced kind of photography and most typical kind of photographer mean they have to love and support every aspect of photography and every photographer? (If you believe serious amateurs and professionals are the only real photographers, or the only deserving photographers, you have an ego problem.)
Aperture had a 10-year life. That's all, in the roughly 40-year history of Apple. You can assume that 10-year period was an expression of love, but it wasn't. They tried something, and it didn't pan out. In terms of Mac sales to photographers, the fact that Adobe runs on Mac has been far, far more important than the existence of Aperture. If you look back on the history of Mac's appeal to creatives, it almost never had a thing to do with Apple-developed pro apps - it had to do with Apple providing the right hardware and OS - a platform conducive to creative pros. Often, the launching point was the equivalent of a toy - a simple, proof-of-concept app bundled with the OS that inspired the imagination. If pros needed more, third-party developers typically addressed those needs.
I remember all the threads here, long pre-dating Aperture's announced demise, from professionals and serious amateurs who had absolute dislike and distrust for Aperture. A pretty hard group to love, if you ask me. Aperture's editing or RAW-processing functions could never measure-up to Adobe's. People couldn't understand the very concept of a database, or trust their precious photos to a database they hadn't designed on their own.... No, Aperture was never the kind of success that Final Cut and Logic Pro have been.
Seems a simple decision to me. Focus on the kind of photographers who are most meaningful to Apple's business. Leave professional photography apps to other developers. That's neither love nor hate, that's a pragmatic business decision. Apple produces only a handful of professional applications; one may as well ask why Apple doesn't love accountants, apiarists, architects... all the way to zoologists.