Wait, let me make sure I understand -- you're objecting to his promoting of a business interest on his own blog? By telling a story about he got involved? I dunno about you, but if I had a blog with a gazillion loyal readers, I would promote the hell out of my own projects. What, uh, else is something like that for? I'm with gruber on this
You're right in terms of the '90s and early aughts, but I believe the commenter is referring to current market conditions. That is, "Apple ended up eating almost all of the profits in the PC market" means since about 2009 or so. Between MacBooks and iPads, Apple claims an outsized portion of the industry profits relative to its market share, as with iPhone.
Somebody correct me if I'm wrong: hasn't Apple seen its Mac line market share grow for something like 26 straight quarters? And, since they're high-end / premium devices (> $1,000), the margins (and therefore profit) are higher (again, like iPhone).
It's true, nothing that combines its simplicity, focus, and ease of use. Though fortunately there have been a number of great indie devs who've stepped in to make terrific graphics editing software: Acorn & Pixelmator are among the two best. My personal favorite (and closest true alternative) is Sketch:
Design (especially UI) is an exercise in solving problems and designers often arrive at similar solutions. That's OK. What matters is whether the user gets what s/he needs, not whether the UI is memorable. Indeed, the less computer administrative debris, the better. I design for a living and the best success I've had is when the UI gets out of the way of the content and task.