But how often do you see a major company betting itself on one single product line? Not that often I say, but that might be because I do not know industries outside IT and Cars that well, and also you tend to forget the failures and the associated companies.
One reasonably well-known failure was the Schlitz Brewing Company that went downhill in the early 1980's after betting on new technologies in making beer to produce a less expensive beer to produce and increase margins. In the process though, the beer, even for American beers at that time, went of to taste even less, if that is possible and also the beer looked awful. So Schlitz lost it's customers and went downhill and was acquired a few times. Their most innovative Brewery, as far as technology goes, still exists, is owned by Anheuser-Busch and produces, well, you can guess it by now, Bud Light.
Anyway, enough of interesting things such as cars and beer, let's get back to boring computers again. Some of the biggest bet-the-company project we have seen are in the IT industry, one is when Microsoft decided to go with Windows, skipping out of the development of OS/2. If you look back at it now, and consider that at that time, IBM was still the dominant player and also that IBM had brought Microsoft to the position it was in (by giving them the right to print money, sort of, in the shape of allowing Microsoft the rights to DOS), this was pretty risky bet by Microsoft, but it worked out. There were more IT bet-the-company projects in the 1980's, from Commodore and Atari and so on, but they were largely failed. Also, we have Apple giving us the Mac, but in this case, Apple as a corporate entity never was betting on the Macintosh until it had proven itself in the marketplace.
But I think that one of the most substantial bet-the-company projects ever, in any industry, was when IBM bet on the 360 architecture in the beginning of the 1960's. At the time IBM had a huge array of conflicting and incompatible lines of computers, and this was the case with the computer industry in general at the time, it was largely a custom or small scale design and production industry, but IBM was such a large company and the problems of this was getting obvious: When upgrading from one of the smaller series of IBM computers to a larger one, the effort in doing that transition was so big so you might as well go for a competing product, the effort was actually similar, you had to redo everything. So IBM was getting some serious competition from the "BUNCH" (Burroughs, Univac, NCR, CDC and Honeywell) as they were called later when General Electric and RCA left the field of computing in the late 1960's.
Yes, the IBM 360 was truly revolutionary. It was a whole new range of computers, including software, hardware and peripherals. It had a whole bunch of features we now take for granted, like the 8-bit byte addressing (yes, this was not an obvious feature and the term "byte" itself, although not invented for the 360, was first used by IBM and was made 8-bits and nothing else with the 360-series). The risk that IBM took with the 360 series was enormous, and this is another factor of what bet-the-companies all about: taking a really big risk. Looking at what Xerox did, or rather didn't do, with PARC, explains a big chunk of why PARC was a failure, in terms of turning Xerox around, and why the 360 was not. The 360 really did turn IBM around, and many at IBM was not happy with the way that the 360-series was developing and what it was doing to existing IBM product lines, but the IBM management at that time stood by their decisions. As for Xerox in the 1970, they were much less supportive of PARC (and this is a gross understatement).
Anyway, the IBM management that dared taking the 360-project is to be applauded, and I think we need more of this kind of daring management, stuff is just happening too slow and it's time for a quantum leap. And although there is a risk to betting-the-company, the gains can be enormous and the effects of NOT taking that risk is also betting-the-company (look at those office equipment manufacturers that didn't dare to go into computers).
I think this is only of the issues with many Open Source projects, they are run and supported by people using the project the way it works today, and hence has limited interest in taking a huge risk at some new, unknown technology that currently has limited value for them. As Henry Ford said: "If I had asked people what they wanted, they would have said they wanted a faster horse".