"But in my opinion, it is far easier to replace a fuse and one easy to diagnose component, than "
Wheels, personally I agree with you but Stateside it typically will cost you $75-100 to bring any electronic device into a shop for an estimate--not free but applied to repair costs. Factor that against the replacement cost fo the device (i.e. a $300 five year old tv) and folks just don't want to know something "easy" blew, all they know is "time to buy a new one".
What can you say.
Last time I had an old 19" Trinitron repaired (about $110 ten years ago) it lasted another year and then something else blew--apparently among other things, electrolytics age and blow much easier than they used to.
And that's far beyond the point of sale
. If your diode and varistor bumps your retail price
to $199 and theother guy is selling at $195...you know which one sits on the shelf and which one gets the market share. Sadly, the mass market usually gets what it demands: The cheapest possible goods, and don't bother them about anything except logo and style.