I tend to kill one after a few wet rides. Problems of an external bearing.
But most people don’t kill them after a few wet rides, so it can’t be just an inherent issue with the design.
I just replaced the NDS XT one in my Ragley- fitted the BB when I got the frame, it was previously in my C456, and so was about 9 months old and got ridden constantly. It has not been a very dry summer, autumn, winter or spring in Scotland 😉 The DS one is still fine, the NDS one had gone loose.
If you’re going through Shimano ones fast, you might want to look at the Gusset EXT24- it lasts only a little better without servicing, but is easily dismantled to clean/grease bearings, or to replace them, and uses standard bearings, and doesn’t cost much more.
Alternatively, continuing my overtightening theme- Hope are far more resistant to home mechanicking than Shimano 😉