I saw where it started, but I think you have a very skewed perception of the general Tesla population. (I don't mean this as an insult, just an observation).
There are a lot of Tesla owners who are younger, don't have paid off mortgages, and who can not pay $100k in cash. It's one thing to cut a $100k check when you're 70 and retired and have $2M in your IRA/401k, it's another to do so at 25/30/40/50/etc when you have kids to put through preschool/school/college, a mortgage to pay off, etc.
Also those same people might not have $100k in liquid cash laying around, and might think that a person who does is an idiot. Those same people could have $500k in equity in their house, but still have a mortgage. Those same people might own 3 rental properties with over $1M in equity, but not have $100k in the bank to buy a car. Those same people might have $100k invested in stocks, and think it makes more sense to take a loan out on a car at 1.49%, etc.
It CAN be argued that those same people would be better off in putting that money into an IRA or paying off their mortgage and driving a beater car. But it's not your, or my, place to argue that point. Everyone has a right to chose how, when and where to spend their money. Someone might a bigger house, a nicer car, or vice versa someone might want the bare minimum but to retire at 50. Everyone has decisions to make, and to each their own. But no one is an idiot for doing what they think is a good financial decision for themselves. They might not agree with your school of thought, but that doesn't automatically make them wrong.
And while it was an assumption/mistake for the poster to say that you took out a car loan as big as your mortgage, your response was far more condescending stating that people are idiots for taking loans on depreciating assets.
/soapbox