In the first project I worked on at MS we were entering a new, established market with multiple strong competitors, and because Microsoft at the time did not have the right tech stack to do web services, the initial tech choices were dubious at best. The first version looked great, but under the hood it sucked like you wouldn't believe. Then sales somehow sold it to some pretty large/important customers, and the team had to spend the next 2 years fixing things "under the hood". Now it's one of the leading products in its market.

My second project there was about enabling the desktop version of Office to be rented and backed by online services. At the time the idea was novel, and nobody believed it'd succeed, _especially_ because Ballmer was pushing it pretty hard. But succeed it did, wildly.

I know multiple such examples anecdotally as well, from friends. The initial versions of Azure seemed like a waste of time also (VMs topped out at like 32GB, everything sucked mightily throughout the entire stack, nobody thought it has a fighting chance). Today it's the second largest cloud, and growing rapidly. Still kinda sucks though. :-)

The initial version of Bing crawler was pretty horrible also (index team had more time, so their code looked squeaky clean in comparison), and it spent years trailing behind Google until they figured out how to close the gap (with "hiybbprqag" thing - the press got it wrong, they weren't "stealing" Google results per se; they augmented training data with clicks that come from Google search pages IIRC). Today Bing powers Duck Duck Go among other things. It's still not a wild success, but it's most definitely not a waste of time either.