This subscription issue is not nearly as cut and dried for me.
Take the Pro Tools support subscription example. This is not a subscription model because if you stop paying you can keep using the last version that you installed. They were asking $199 per year to support the standard Pro Tools system (which excludes Surround mixes etc). The full HD system is $599 per year. My problem with this model is that there is no evidence that Avid are going to deliver any meaningful upgrades in the subscription year. If they published a road map of upgrades then people could assess what they were going to get for their money.
Based on their record to date, I would be much more confident that Steinberg would deliver value for a support subscription. To me it would make no difference if you are talking about £80 per year subscription as this is what I pay out anyway to get the latest version number.
However I agree if Steinberg (or Avid) went down the Adobe subscription route they would lose many customers. Unlike Avid, Steinberg is not strapped for cash so I do not see them taking a risk like this any time soon.