Because of better support from TI, BB always had a more professional feel than the Raspberry Pi, specially for documentation etc. It's a fine chip, if you can source it (haven't messed with anything from Octavo, but it seems solid to me). All the software issues are pretty much solved and upstreamed at this point.
I think the main advantage, for my hobbyist self at least, is the 0.80mm pitch BGA which is doable on OSHPark.
TI's more recent AM625 is 0.50mm pitch, which is too small for OSHPark 5mil trace/space, lol. Perhaps a bad reason to a professional but... I'm filtering out for chips that I can actually affordably make a PCB for on a hobbyist scale.
Old does not mean worse.
All of the extra gorp on newer chips takes a LOT more power.
For example, that 10-year-old chip runs Linux quite reliably in a 5V-500mA power envelope--something the RPI series never did.