FWIW, it was Birmingham who first started giving out Unconditional if Firm offers about 4-5 years ago. Despite their spin about it reducing stress for students, it was obviously a marketing tactic, as at the time they were one of the less popular Russel Group universities. The year after, the idea was quickly picked up by other universities that were around mid-table and of course this puts pressure on other universities to follow suit. I agree that none of the universities on the list are dreadful, but they all perhaps have reasons why they might struggle to recruit compared to some other, comparable institutions.
I also agree this is a symptom of the marketisation of higher education, not the cause.
In some ways, I feel the early pressure put on students to rush into booking accommodation is worse. With Unconditional-if-Firm offers, if students realise they have made a mistake, they can at least be released from the offer with no penalty and find another option e.g. via clearing. If a student has been pressured to sign up for accommodation, they may face financial losses if they do this, which puts even more pressure on them to go to a uni that might be wrong for them.
Unis seem to be opening up their accommodation (on a first come first served basis) earlier and earlier every year- often before applicants have received all their offers. I do think this puts a lot of unfair pressure on applicants, particularly those who may be nervous about the alternatives (such as private halls) as they can be more costly/less well supported.