Would have thought it was painfully obvious to everyone even tangentially involved that they're on their last legs? I mean come on....
Half this thread is people with links to the programme discussing how dire the HST situation is at Scotrail. The other half is enthusiasts sticking their fingers in their ears and acting as if nothing's wrong with their favourite trains, in spite of overwhelming evidence....
That's clearly the way you're interpreting it. I'm seeing a company which has come out of a challenging overhaul which was done on the cheap, finally made some of the changes which should have been made all along, and is starting to make progressing on training and retaining engineering talent. I'm not seeing the units do any worse than quite a lot of new stock in terms of miles per failure, or a company which would necessarily be doing any better with any intercity grade stock. It's not at all clear that switching horses in the middle of the race is a winning strategy here.
As to the enthusiast bit, I'm mildly interested at best, and in terms of any personal attachment to HSTs I couldn't give a toss whether they replace them tomorrow. As a general supporter of public transport I want there to be a reasonable quality of service to Inverness/Aberdeen, and as consumer of Scottish public services generally I'd like to see that done at a reasonable price so that there's less of a black hole in the budget.
What I don't see is any strong indication that replacing the HSTs is a cheaper alternative, likely to provide a better service, or in any way inevitable prior to 2030.