The vast majority of buses do not have seat belts. Studied have shown them to not be needed. Not sure where your info comes from but if there is an incident between a bus and a car? That bus is coming out of it in much better condition. It's not a case of a runaway bus careening into stuff!!!
And more buses mean more costs....cost of the actual bus, fuel, maintainence, drivers, etc. No one stands on the DME because it's a tour bus style. It was not designed for standees. The park buses are the same style as public transit....built and designed for standing.
Huge difference between DME waits and park bus waits.
Why are wheelchairs and
ECVs strapped down? Seriously? Because they are not capable of holding onto something!! Pretty simple. Passengers on buses are capable of holding onto overhead straps and poles.
This is an interesting subject..one that crops up every so often. Does anyone seriously think that Disney and cities/municipalities actually put buses into service that are going to cause injuries? There just aren't that many instances of serious injuries on buses. That's just a fact of life. Yes, there are some. But accidents happen. Me? I would rather be standing on a Disney bus than sitting in a car on Disney property and being in an accident. Those on the bus are substantially better off, even those standing, than those in that car.
I have never, ever had an issue standing on a bus at WDW. And I've been there more often than most people. My biggest concern? Being on a bus that has to stop quickly and being hit by one of those massive double strollers!!! I was on a bus last week, at WDW, that had a huge jogging stroller tied down!! I was amazed that the driver allowed that. That stroller should have been folded up. And no, there was no child that had a special situation using that stroller. Just a family that begged to be able to bring it on the bus as is. Made me somewhat cranky since it then took away three seats!! And that was for park opening, so you know it was a crowded bus.