Well, the general stigma stems from the original batch of Moto devices that actually had you sign into a service to use features you probably didn't give a hoot about in the first place. The new Blur running on the Droid devices doesn't have that crap, and for the most part is just Android with their widgets and launcher added on.
What do I, as in me, not personally like about Blur?
First, and foremost is I just don't find it aesthetically pleasing. The colors, the icons, the widgets, bleh. This was just a minor annoyance, because as with any rooted/deodexed Android phone, I could just change the framework(theme)
The second thing is that they removed some of the functionality of the stock programs in favor of their own. I don't care that Moto changed it. I care that they changed it, and it actually functioned better in its stock form. Basically, they could have done us all a favor and left it alone. They completely hijacked any use you cold have gotten out of double tapping the home button (anyone who has used quickdesk knows why this is bad) and the long press function of the search button. I also don't like what they did with the contacts. The stock contacts allow you to create a small shortcut of a contact which you can then interact with. Touch the icon, and you get their latest social update (if its synced with gtalk/twitter/facebook) and you get all of the available options to contact them. Moto 86'd that in favor for their own contacts and social widgets which I personally find obnoxious.
Anyway, this is all purely subjective, as many gripes with Blur are. I'm just one of the few actually making a note of that, and not passing along my opinion as if it is the gospel. Someone else may dig the widgets. Overall, their phones still function great, run fast, and have pretty decent battery endurance. The things I didn't like, I was able to either replace with something I did, or worked around it.
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