Overall, no complaints. Most CMs are quite friendly. Remember, you're dealing with many different personalities, not one-size-fits-all, not matter how hard Disney tries to make it that way. My version of friendly is a bit reserved compared to others who are more outgoing.
I think part of what people are seeing is the sheer volume of CMs--WDW alone has many thousands more of CMs in all positions than they did during my first visit in 1981. It's harder to find people with exactly the right personality and attitude for every position--and my understanding is that Disney has modified its training significantly. Both would affect how CMs interact with guests.
And CMs are human. No matter how hard they try to leave issues from home at home, some inevitably have to affect the CMs day. It's pretty easy to walk away from the minor issues, knowing they will resolve themselves or be there to handle later. But some of the heavier ones are a bit more difficult to shed, no matter how hard one might try.
And with all of the focus on various boards about the magic of a Disney holilday, some people have developed unrealistic expectations of a Disney holiday. We have to create our own magic--Disney provides a conduit and sometimes a bit of a push in the right direction! :)