For Broadcom, the Pi might not have been such a big deal, a single home use router with a Broadcom SoC might easily sell 50 million units, and there are plenty of home use routers for sale with Broadcom SoCs in them (let's say, we have 100 brands/versions, that's at least 5000 million chips sold over ~10 years), but the brand name and support from the community (which is bigger in numbers as well as diversity than any of the big tech companies) is pretty much priceless when you hit that millions number and up.
I hope QualComm and their Snapdragon isn't the last one to nudge closer to availability, there are plenty of others that would be welcome to join. While being able to buy the chips themselves isn't the biggest improvement, the fact that they are actually interested in helping with some open drivers is a major improvement!