Why do people like this lens? I have it, so you'll have a clue as to why this person likes this lens...
I like this lens because it's fast--it's a 1.8 which is GIGANTIC! It drinks available light, and allows me to shoot some great stuff in low light which would be difficult otherwise with either of the kit lenses. I like its size--it's small, and the right size to get in the pocket of a jacket or a hoodie and take along for whatever I'm doing.
The lens stops down to f/22 and returns TACK SHARP images. I've had some issues with it, getting it properly focused, but I worked all of that out and now I really can't complain because it's one of my favorite lenses in my bag. It's not menacing or threatening and when you point it at people they don't get freaked out.
It's cheap. You can buy one from a retail store (Wolf, Ritz) for around $110, and can find it on the internet for less than that.
I'm also shooting with a D5000, and while it doesn't autofocus, it's still important to learn how to manually focus and appreciate the AF features when you've got them. It is an absolutely great lens and I'd suggest it to anyone looking for a wonderful short length portrait lens or food photography lens.