On top of that, it's the difference between monthly costs for the company. Netflix, Spotify and Gmail all have monthly costs in terms of storage space, bandwidth usage, server maintenance, etc that users are directly affecting. You're paying for the content to always be available, to be available quickly and to not have limits on what you can and can't access.

Desktop software on the other hand has no direct monthly costs other than phoning home once a month. You could definitely argue that iterating development costs should be factored in here, I can't imagine that being a deciding factor in moving completely to this business model. I'm sure if they offered a low cost monthly subscription and a perpetual license option, they wouldn't have any issue offsetting development costs. At this point, they could even raise the price of perpetual license (hell, I seem to remember paying $200 for mine). I'd gladly pay an increased price with the knowledge that my software wouldn't stop working, especially given how many hours of productivity I gain by using their software.