They royally screwed up by signing an exclusive deal with the back-then no-name Microsoft company. IBM created the 3 trillion behemoth that Microsoft is while killing themselves in the process.

It's really sad but also infuriating: had IBM not fucked up and not signed Microsoft, that mediocre company that Microsoft is would have gone nowhere and we wouldn't have to suffer their turds since decades.

P.S: in their dying breath (and I know IBM still exists), they did commit one billion dollar to Linux early on (which back then was a big deal). When we see the tens of billions of devices that now run Linux, IBM at least partially participated in Linux taking over the world. So there's that.