Obviously, not all SaaS is created equally and a recurring fee isn't always the best idea. Especially for SaaS or PaaS offerings that people aren't used to paying for in the first place or are trying to disrupt services that are free.
Recurring monthly charges by no means need to be the default and customers should be wary. What if they don't like it? Is there a cancellation fee? How is the time billed - is it hourly or monthly? How much does it cost to upgrade to a better tier of service (if one exists)? If they work in a company, will they need to get monthly approval to continue the service, or (speaking from experience here) will they be bugged by their forgetful accountant every month for the charge on the company account? Probably most of all, what happens when I don't pay (mentioned in the article) - does my service suspend, is it limited, am I forwarded to a collections agency?
"Buy-to-own" or "Buy-to-access" is a much simpler model - far fewer questions need to occur on the path to payment. There's less value that needs to be determined to justify the expense, even if the initial expense is higher. Some of the same questions above still apply, like, "what if they don't like it?" - but the answers tend to be simpler ("You get a full refund" vs. "You're S.O.L. and still owe us for 72 hours of processing time", etc.).