I'd prefer not to dive too deep into it, but here's some of it.
First experience walking in, one security guard was telling us to do one thing, we listened to him, then another security guard screamed at us for doing what the other guy said. Within the first hour of being in the park we saw guests getting yelled at 5 times. It was a very unwelcoming way to start off our first day at Disneyland. Had that been it, I would've just written it off as bad luck. We also found the cast members in general to really not be very friendly like they are in Florida. They seemed to act like they didn't want us to bother them by talking to them. There seemed to be very little of that Disney passion that I'm used to from the cast members. Oddly enough, I found more Disney passion from the Magic Mountain employees than Disneyland's.
Beyond that there were a few other things I don't really want to mention. Then add in the park being borderline filthy (California Adventure was quite clean though), the poor air quality, the disgustingly dirty parking garages, poor signage to get from parking to the park, and some other minor stuff.
I did love a lot of things there as well, specifically Cars, Indiana Jones, Matterhorn, getting to do Mr Toad again, and the Haunted Mansion overlay. But not enough to where I'd want to deal with unpleasant cast members. To be honest I feel like I need to give it another chance, since people don't seem to have the same experiences, but I just don't see making a dedicated trip out there ever again, especially when I could make a trip to World or Cedar Point or even just drive to the local Six Flags.