Also, traditional automakers have full lines (sometimes multiple) of different models. Each with its own refresh cadence. And each which then needs to be supported long into the future. (Yes, there are some common platforms)
I'd say Tesla ignored that future debt, but I think it's more nuanced. I'd hazard they made a wilfull decision that the relative simplicity of electric cars will allow them to avoid a maintenance nightmare down the road by simply replacing whole components (a la Apple).
We'll see how it turns out.
Tesla purchasers, are, to some degree, buying into the idea of the brand. This works if your brand is nice and new and flashy, but I think that traditional automakers would probably suffer reputational damage if they tried this approach, and it is very hard for them to shake old reputations if they manage to get one of unreliability.