smashed his body or head so hard that it killed him.
FWIW using language like "so hard it killed him" is far to generalizing or at the very least it can be misleading. Certainly more information will come out hopefully understanding things like an estimated amount of force but purely and only as a general comment each person's body can be susceptible in different ways. Different health conditions can affect each person's body differently.
A random example is my neighbor about 10 years ago fell off his ladder and hit the back of his head, he had a moderate concussion for that and was unable to under doctor's orders to do pretty much anything that would be cause for concern for several months (things like mowing the grass were off limits for example). His body is susceptible to a repeated injury in a different way than someone who has never had a concussion before.
I understand people not wanting to finger point the "blame" (and I use quotes specifically as blame may not even exist here as we have no true information as to what happened) on this man's medical condition but it is worth mentioning and keeping in mind that it can be a contributing factor especially if we're talking about force required to be fatal.
That doesn't mean the ride wouldn't adjust things or that it couldn't be laid upon the design of the ride as well but just that when you're talking about someone with a pre-existing condition or prior injury it may affect their body with either an injury or death involved and the ride itself. If the ride didn't have warnings I do think the conversations and investigations would be drastically different (people are using them to determine their own personal risk threshold and without that they don't have guidance).
I do agree that no one should simply label someone in a wheelchair as someone who shouldn't have been riding the attraction which I've seen a lot of comments that people are doing but I don't think it helps either to dismiss that depending on the condition, depending on the actual force sustained, depending on if there was an injury related to a piece of the ride or the person themselves that it could be part of it. It's more about not trying to paint a broad brush anywhere.
And lastly the TMs, most especially the ones who were working that time period, should be kept in mind here. I do know a TM, one who does work Stardust Racers, and even though they were not working that day it has greatly affected them. I cannot truly cannot imagine how his (meaning the man who passed) family must feel but in relation to people commenting on the situation the TMs are also impacted.