And why is this bad? Who said a brand/company is entitled to a certain amount of sales just because they exist? Aren't we in capitalisms where it's sink or swim and the market/customer is right? If a product is volatile maybe it's not good and people should orient to other brands, no?

If Tesla bins it, other better manufacturers will pick up the slack if the EV demand is there according to market forces. If the EV demand isn't there, maybe the EV hype was a bubble that was gonna pop sooner or later?

It's not bad that it happens, it's bad for Tesla if they are marketing their product as high-end/luxury while their product very obviously lacks the attributes, such as a stable/predictable value over time, that competitors' luxury products have. Someone deciding not to buy a product, for whatever reason, is the system working as intended. If Tesla can't produce a product people want to buy, Tesla will suffer the consequences, as they should. If they don't change their marketing or improve their product in the light of low sales, that's on them.