More generally:
The availability of technology will eliminate a lot of these worries. How long ago were MIG welders out of reach of the average home-mechanic? I remember my high school had a CNC lathe and it was worshipped as a piece of true unobtanium... Nowdays you can get a Chinese TIG from Ebay, and even 5-axis CNC mills aren't worth too much.
Similarly, when I look at cars with known weak points, the aftermarket always fills the void. ~15 years ago, I said "a lack of available gearboxes will kill off Subaru WRXes in another decade or so"...
In reality, you can buy brand new internals from a dozen different suppliers.
Likewise the $8k replacement cost on piss-weak Volvo FWD automatics was prediced to be their downfall once the cars were worth less than $20k - the rebuild kits are $270 + freight out of the USA (and funnily enough, the cost of a rebuild has declined as thevalue of the cars has declined..). The slightly later FWD Volvos had $2500 drive-by-wire throttle modules as their weak point - now available for $370 exchange on Ebay...
Same sort of thing is true for older bikes - there's no reason to think it won't also be true of the bikes that are currently moderns...
Also: TM Bill earns my "Drunken Post of the Month" Award.