Whoa. There are some strong opinions there for this early in the morning.
Look, I'm not saying Feist is a great writer, because at the end of the day, he isn't. I think his books are good, and the overreaching story is strong, even if it is mired in the genre a little, but maybe that's to be expected. But he's not great be any standards.
He wrote about the RPG world he and some friends created, but another way of putting it was that he and some friends created a world for him to write about, and they played games in it to explore it thoroughly. That is what D&D has done with Tolkein. There's nothing wrong with that, and in fact it adds some depth to the books that wouldn't be there otherwise.
And when I said Tolkein wasn't, technically, a good writer, it wasn't because I don't have a strong point, it's because I was trying to be polite. What I should have said was "I don't think Tolkein was a good writer". I think he's clumsy, and prone to self indulgence. By today's standard LOTR would never be published in it's current form. There a several parts to the story that are just boring, and unnecessary.
That's not to say I don't respect him, because I do. I think the man was a genius, and he created modern fantasy, a genre I absolutely love reading. He invented an entire language! The man was a God. He just wasn't a very good writer.
But you're right, we're talking about Feist here. It just seems to be that you haven't read Magician recently, and you didn't read it deeply when you did, because a lot of the points you're making are a little shallow, and unrealistic.
The Janny Wurts books, three in all, fully explained the Tsurani. It took three books to do that effectively. Exactly how much time did you expect Feist to spend on that in Magician? You say there aren't any 'evil' people in Midkemia (not Crydee, which is a coastal settlement, not the entire world). What you mean is that Magician followed the plights of likeable characters who were all fighting on the same side because their world was being invaded by a warlike race they'd never encountered before and were having trouble pushing back. When did you expect Feist to segue away from this story to start exploring the less likeable characters? I'll tell you when, in the next book - Silverthorn.
Now, I'm not saying you're wrong. I think people got very excited when Magican was published. I also think it did generate a lot of growth in the industry, but at the end of the day, it certainly appears to be lacking a little by today's standards. It was written over 20 years ago. It's not great, but it is good. Feist isn't a great writer, but he's good at what he does.