I did meet a guy recently at a local bike meet, who had over 140,000 miles on his owned from new K100RS, and he'd never done this job.
Of course, you shouldn't formulate opinions in the context of one persons experience, but I have some reservations about this.
Splines stripping to me, suggests alignment issues rather than lack of lubrication.
I remember this exact issue coming up on the Chromeheads forum (catering for the BMW cruisers), and one of their guru's did indeed identify a common spline misalignment issue with this model, resulting in transmission failures.
Anyway, we pays our money and take our chances.