Bambu is not (never has been?) targeting 3D printing hobbyist but everyday people; and for them cost/reliability is more important than running your custom slicer. Until there is a serious competitor that has a polished and cheap printer, Bambu can alienate all of the open source community and still be fine.
Bambu is following Synology's footsteps here. And just like Synology, they will wake up to press at some point and common wisdom "don't buy Synology, the elite moved off when Green came out and now the rest are leaving too".
I own the most expensive Bambu (The H2C) - and even I am willing to admit that the snap maker is a great printer, and a better technical path in someways then the H2C vortek system for anyone who doesn't care about engineering filament
Most commenters here will value the openness of Prusa, but most lambda users will have limited budgets that Prusa does not cover. The U1 is a great attempt at taking on BambuLab head front, with interesting features at a reasonable price point.
In the end, a lot of people (including here) are using an iPhone even though it's locked down to a higher degree. Some people like a walled garden, some don't care.