There are two issues here. The first is around what constitutes delivery of the services, where I take a hard view that the timetable is an intrinsic part of the contract, meaning that it is a contract to convey from X to Y at the times stated in the timetable at the time of booking (and, yes, I know about attempts that DfT/the industry have to flex that particular point).
That's a view on which there can be legitimate difference, both in principle and on the detail of the thresholds and levels at which a delay should trigger payment. That isn't really fundamentally about the OP's original question of whether DR is destructive.
My comment, to which that post is a reply, was that the idea that "the money is leaving the industry" is in itself destructive. I don't dispute the bare facts that money refunded to a customer is "lost" and, in another life, I'd of course try to make sure that any compensation has to be used with my firm so that the impact is limited to the cost, not revenue.
However, what the statement also includes is a statement of entitlement, that somehow once money has been paid to a company or industry, that company or industry is entitled to retain that money. It's that concept that I take deep issue with, and I believe the widespread belief in it is a symptom of deep failings within the rail industry. The logic of the statement is also evident in the claims of the industry that fare rises now are justified to pay for investment later - a laughable claim that no other industry dares make*. It implies that the rail industry is somehow above ordinary mortal demands, and that those who pay serve it, not the other way round. It is also evident in any number of customer service failings, where operational convenience is put first.
* - there's a possible exception in aviation where airports raise fees in advance of new work. As Heathrow demonstrates, that's not a well respected view.