To OP: YES there are people who rent a scooter thinking it gives them a better access than people not in one. Every time I read these posts I just start

I do not "look" disabled but alas I am. (As you read keep in mind I have a very weird senes of humour--don't mean to offend anyone but....)
As a scooter user I will tell you some of our "secrets":
1. Almost all of the lines in WDW are mainstreamed (this is a fairly reccent change) --this means the
ecv fits through the line so you must go through the main line (there are however some lines with tight turns and it is

watching people try to make the turn and then
back up into the people in their own group when they have to try again) Okay not funny all the time but when you suspect it's a faker it is just karma and therefore funny. (YES even us "real" ecv users will sometimes make snap judgements about others.)
2. If you do get pulled aside at a certain point in the line,
you tend to wait LONGER than normal. The reason--there are already a ton of wheelchair and scooter people in front of you. It is very frustrating to either wait in the standby line with people, then get pulled aside and see the people who were behind you (and many more after that) pass by you or you take a handicapped accessible route and see the stand by line flying through while you wait behind several other parties (IASW is a perfect example: the stand by line could be walk on but because there are so many ecv/wheelchair families lined up at "their" entrance you are waiting 10 - 15 minutes or CM's are sending boats out EMPTY.
Even if you don't need the "accesible" vehicle--if someone in front of you does most times the CM will not load you until that party has loaded (first in first out). So now you have to wait for the parties in front of you that need the ONE accesible vehicle (while everyone in the standyby line keeps getting on).
3. At "reserved viewing areas" for parades/fireworks, the CM's will sometimes limit the number of people you are allowed to have accompany you to those spots. Travelling with a large family? Sorry you will be split up. And they pack you in wheel to wheel so you can't move until the people next to you do,
it's like scooter dominos.
4. Your view of any park will be limited to the backside area of the people around you. If you are really tall you may see slightly higher but this does make for "interesting" viewing. As long as you aren't close enough to get a whiff when they pass gas. (You wouldn't believe how much "cheek" is acceptable for public viewing--and on some people who really ought not to)
5.
Once you enter a scooter/ecv you become "invisible". (hey--that's a super power!) People will stop dead in front you, try to jump across you, drag their child in front of you, shove their stroller in front of you, try to "outrun" you when crossing a pathway, stand in front of you if you leave even 1/2" for parades and shows, refuse to move from the accessible curb areas, cut in front of you in line for snack carts and food, talk to the people around you but not you (you also loose the ability to speak), keep their cigaratte level with your face,
and for the record, no matter what ---it is ALWAYS your fault--no arguing with those people.
6.
You will receive the best medical care and advice in the world at WDW. People all around you will be able to tell, SIMPLY BY LOOKING AT YOU, what your diagnosis is, if you are faking and will be able to diagnose your healing time (usually right around the time you have the nerve to actually WALK into a ride or attraction). You save TONS of $$$$$ just by listening to what the people are saying about you.
So yes, I am sure there fakers out there but they are usually in for a rude awakening when they try to put the reality of an ecv into use at a park.
And did I mention the people who feel free to yell at you, grumble in your face and make snide, rude, nasty, unfeeling comments to you becuse they have judged you "unworthy" of an ecv?
The flip side is:
1. People (and generally a lot of younger tween/teens) who will
hold open doors for you.
2. People who offer to "grab you something" when they go to a snack cart and you all have been waiting together for a show/parade.
3. People who see you sitting still for awhile or looked "peaked"
ask if there is anything they can do for you.
4. People who offer to carry your tray when you are in line for food.
5. People (generally men) who see you struggling to assemble your ecv in the parking lot and offer to help.
6. People who will make their kdis or themselves sit down at a parade if they see you a few rows back.
I prefer to focus on these people. Walt's kind of people.