The “subscription but keep forever on cancel, sans updates" licence model is just so much more honest than pretending that purchases would be one-time investments and so much less of a risk for the buyer than a hard-stop subscription.
I think it's also good for the product, the right balance between the failure modes of being able to milk existing subscribers even without maintenance for the hard subscription and change for the sake of change that you see with classic one-time licencing where reasons for paid updates have to be invented even when there is nothing to improve (edit: how many great products have been ruined by this?).
The perpetual license fallback saved me when my license expired. Due to the US holidays it took our purchasing department a week or two to renew my license. In the mean time I was able to fall back to an older version, and upgrade once my new license came through. It was very easy and straightforward to do in both directions.
I think it's also good for the product, the right balance between the failure modes of being able to milk existing subscribers even without maintenance for the hard subscription and change for the sake of change that you see with classic one-time licencing where reasons for paid updates have to be invented even when there is nothing to improve (edit: how many great products have been ruined by this?).