The subscription business model is all about:
A) pushing out updates as they are ready, and not storing them up for a big new version release that you need to once again sell to customers.
B) More importantly, getting a predictable revenue stream from the software offering, so you don't have huge dips and spikes in revenues around new version release dates.
Those aren't necessarily bad reasons to move to subscription services. It's not in an organization's interest to see their important suppliers suffer and start shutting down operations/reducing investment in future products. (Granted, sometimes I think that Microsoft is an exception to that rule.) But you have to price things carefully to avoid outright soaking of customers, while providing them with value in return for the value their change in payment terms is providing to you.