They hired bzr developers, including some really bright folks (Robert Collins, who I knew from the Squid project, was one of them, but there were others).
Had git not exploded in popularity and pretty much decimated the competing DVCS projects (or just grew so much faster that the end result was the same...tiny percentage user base for everything other than git), the landscape may have looked different. It took several hosting services a while to figure out that git was all that mattered.
Hell, even Microsoft and Google gave up on hosting code. If they can't do it, how can we expect Ubuntu to get it right enough fast enough? Github both got lucky and made some very good decisions very early. Survival bias looks like anybody could have done it...but, a lot of stuff had to fall into place, and it wasn't obvious to everyone what it ought to look like or how to get there.
To be clear: the resources+alternatives aren't a problem, it's big G's inability to convert them into a revenue stream with light support/maintenance costs.