In a world where most stocks don't pay dividends, rationality is kind of out the window. As long as these companies don't go outright bankrupt, or have to sell a bunch of new equity to stay solvent (and therefore dilute existing shares) there's no actual monetary consequence of a company doing good or bad. It's literally just going on vibes

Honestly, in a company that isn't returning capital to shareholders, I don't see the point if it's a company that isn't somehow subject to a potential acquisition. If you don't have a path to monetize your stake, why buy it? These days, just vibes. TSLA and SPCX might as well just be another crypto like Bitcoin