Some things like capacitors have a lifespan just due to their nature.
A McIntosh owner might also enjoy knowing that accidental "user error" type stuff can be repaired. It's pretty difficult to actually blow out an amplifier unless you're doing some real torture test type stuff; the fuses should blow before you can do any real damage. But still, after having plunked down megabucks on an amp, it's probably nice to know that your $10K or $20K investment can be repaired if you really manage to screw something up.
Not that I personally would ever consider owning McIntosh gear. I'm sure it's nice, but at the prices they're asking... I'm good.