I'd think it's the second lesson that will be learned.
Musk has been on the verge of failure for years, and cracks are showing now more than ever before.
I'd hate for everyone to stop dreaming for tomorrow just because one guy couldn't pull off everything imaginable.
For all the good things Musk does, he also does a lot of bad things. Including but not limited to dreaming up absurd fantasies to "reinvent" industries he has literally zero experience in (aviation comes to mind, drilling tunnels, underwater rescue, etc) - and everyone fixates on that imaginary solution because he said it.
Not to mention taking credit for all the hard work the actual aerospace, mechanical and other engineers are doing under Musk. Very seldom do you hear Musk talk about how incredible the team is and how lucky he is to have them working on these problems. No, instead he has the gall to call himself Lead Designer this, or Chief Architect that. We all know he's not sitting down and crunching math to design rockets and cars and more.
Look at Hyperloop. People are still wasting money, energy and resources on it, regardless that what we have in testing today are just Maglev trains in tubes... a far cry from what Musk originally dreamt up. Nevermind how impractical or prohibitively expensive and uneconomical it would be to build trains across the US, oceans, across the world all connected.
People want to dream. Fine. But trusting all of the future to just one guy... I'm not so sure.