Respectfully, I have to disagree. Yes, the modern Photoshop is miles away from GIMP, but there was a time when the gap wasn't so large. Given how much money was poured into the development of Photoshop, that should wonder nobody.

Developing a software for 25 years is in itself an achievement. As a user I think it developed quite nicely and added cool features every now and then.

Calling GIMP 'a worthless heap of garbage' is neither polite nor warranted.