it is good to hear these high mileage stories, no reason really why they shouldn't do it with regular oil,filters and the right bits changed out as and when required.
as balance though plenty of Audi's and Mercs on really high miles.
I have a theory on why its not so common on Alfa's and have argued it with members of my family that drive Volkswagens and BMW's.
I think the problem is our cars depreciate so quickly that people start cutting corners on maintenance earlier in the life of the car,this can mean putting things off and extending service intervals beyond the recommended...this leads to the cars being unviable economically at as early as 7 years old as you may have a cambelt,clutch and flywheel,wishbones, all come up in the same year if they have been ignored by the previous owner,thats 2k at a good indie,god forbid you happen to know no better than a main dealer who will charge close to 4k for that lot...
The rise of the PCP way of car buying its easy to see why owners look at a bill of £1000 and decide to put it towards a deposit on a new vehicle, it's not just Alfa that suffer this, only last night a mate phoned me having bought a Mazda 3 about 6 months ago for 3k. a replacement DPF,EGR and a MAP,MAF and a couple of other bits have so far cost him £3.5k! and the car is still running in limp mode.
most of us guys are handy with the spanners and source our own parts so have a different view, I asked him to tell me the cost of the parts and the MAF was charged at £289 and the MAP at £120...
we know those parts were likely to have been bought by the dealer at ECP for half of that and charged out as OEM at full price.
my point is to run a car above 100k these days you need knowledge,tools and a laptop with diagnostic software or at very least a really honest garage that charge fairly and are cool with you sourcing your own parts.
otherwise a known monthly figure for a shiny new car with warranty and dealer support is far more attractive to most people than the unknown cost of running a high miler out of warranty.