I don't hate buggies, wheelchairs or strollers.. They are to assist mobility at times you need them and I think it's great that nobody is excluded because disney isn't easy to get around, even if you are healthy, there is still times you need some help.
Now what I hate about them is when someone is operating them that shouldn't be. Kids pushing grandma around, medication that says don't operate heavy machinery, ram into people to get them to move, road style rage when upset or irritated, someone who would never get behind the wheel of a car, someone whose vision is impared in a way to impact operating it, etc etc etc etc... Those people I hate and where they get the bad wrap from. I'm all for independent mobility but you need to know the limits of yourself or the person your renting one for.
Now I have had to use one a few times for reasons that are really none of anyones business. I used the disney rental ones and found it interesting the delay they have when starting to move and how much longer it took to stop, even if moving around slow. If you've never tried one of them, you may not know they are like this. I got a new education on how I need to act around them because I needed to be further away and not assume they are just standing still when I went to walk around or past one. It's frustrating at first when you use one..
there is also times of year when guests are more than a little rude.. there are times of year it's really pleasant to be using one.