Competitive pressure, and the "if we don't, someone else will" effect (or Moloch, if you like). AGI- particularly recursively self-improving AGI- is the ultimate first-mover advantage: the first company or country to have AGI will very likely be able to leverage that into keeping anyone else from getting it (if it doesn't, y'know, kill us). This strongly encourages treating all concerns other than "get there first" as secondary.
> Automobile manufacturers and their tier 1 suppliers are the world leaders in automobile safety, after all.
Not by choice they aren't. They are forced to be the way they are by government regulations, which they always bitterly opposed at the time of creation. In fact, capitalism has such a reliable record of "not giving a shit about safety until they are forced to" that I'm perplexed you think AGI would be any different.