I'd invite him to sit down with a piece of paper and a pencil and sketch out how many copies those guys would have to sell at the non-subscription price point every year in order to stay in business. Then maybe he'll fully understand why so many software companies are moving towards subscription models: either they do that, or they go under.
So at the end user level, the question you want to ask yourself is, do I want to see my vendor stay in business or not?
It's quite obvious why a software company wants to move to a subscription model. The question is whether their software warrants it. The aggregator space is crowded with quality free substitutes, which means that the market is going to be more sensitive to price. (In other words, demand is elastic). If I'm going to pay for something while there are free alternatives, I'm going to have to see real value in it. If I'm going to pay someone on an on-going basis, I'm going to have to see real on-going value in that.
I purchased Newsgator Outlook because it was $25 and, at that price, I saw more value in it even than other free Outlook-based aggregators like Intravnews. If it was $50, I probably wouldn't have bought it.
So, yes, if Newsgator can convert everyone to subscription based services, that's a big win from them. It's not clear to me that they can. Take, for example, the comments here which ultimately led them to abandon the subscription-only model for FeedDemon.
On the other hand, why limit your market to only those willing to pay a subscription fee? If they really wanted to stay in business, they would segment the market and offer both the software and the service.