The problem I've witnessed is this creates a perverse incentive to keep the organization using old tech even when its against the organizations best interest. I've seen developers essentially lie to non-software-minded managers as a means of not being forced to learn a new platform.
There's a lot of factors at play. Yes, there's incentives to 'lie' and say "this can't be upgraded". There's also incentives to say "this is old and is bad and we have to rewrite!" - I've seen a lot of resume-driven-development. There are people who will lie to avoid having to learn an old platform as well.
Very true. In my experience the rationale to lie to upgrade has a higher burden because it has to overcome the inertia of a status quo that has at least worked for some time.
It tends to be easier to advocate for a past solution than an unproven one.
To be fair, most of my experience is where software is an enabling function, not viewed as the end deliverable. E.g., control software for hardware. In most instances, the project managers were hardware folks and that tends to cause the problems you might be alluding towards.
