I think what they wanted to convey was not the redundancy of 'reinventing the wheel', but the ambitious scope and from-scratch approach associated with the phrase.

Maybe 'rolled their own' or 'first invented the universe' would have been slightly better.

But does doing something like that once 20 years ago mean they can do it again?

I dunno. I was a kid when Rails took over the world, so I couldn't even begin to tell you why it succeeded in the way that it did.

But I do feel like they probably know what they're doing enough to have a more modest version of success with this other project, i.e., meeting their own needs well without burning up too much money or time. They're still a really small, focused company, and they have a lot of relevant experience.

Well, as with all homebrewn solutions, you don't know if you are reinventing the wheel until you're done. At first, it always starts with "the current solutions that are available do not fit me, but I still could use them to achieve what I want". There was nothing forcing 37signals back in 2004 to roll their own framework in order to support developing their apps, but they did anyway.

And for every Rails out there, there are thousands of internal frameworks with big ambitions that just turned out to be inferior to what's already available. You just can't know it when you start developing. It takes a bit of ego and ambition to go that path, but sometimes it pays off. And my guess is that if it paid off in the past, you're more likely to try it again.