The article makes some good points and is a good starting guide to setting up a dependable stack but I think the author downplays the skill, cost and time that something like Heroku can save. He states "not including developer time ofcourse[sic]."
For those not able to afford a fulltime sys admin that can be a significant expense and bring in unnecessary risk.
Cost: Cheaper, because you're doing the work yourself and only paying for a VPS or two.
Time: A weekend.
If you're running a start-up and you can't hire a sysadmin, yes, managed hosting is a good idea and will net you a reliable system for a decent price. But if you're spinning up test/hobby projects which aren't mission-critical, take the time to build your own stack/servers. It takes a minimal amount of time and energy and will give you valuable experience you can use for the rest of your career.
Despite potentially talking myself out of work, I highly recommend this approach.
Sysadmin is something that you can learn by doing, and any competent software developer should be able to pick up enough knowledge to manage the kind of simple deployment that a freshly minted startup needs.
I don't think you necessarily need a fulltime sysadmin - contract sysadmins do exist (hi!) and systems like Chef can be readily understood by most developers.
If I was moving a start-up from Heroku to self-managed hosting (which could even just be Linode VMs!) I'd include time to train them on what I was doing, and why, and I'd probably stay on retainer for emergency support.
Personally, I'm also more than happy to chat to local start-ups informally and share my experience. (And if anyone in Scotland, particularly the Edinburgh area, wants to take me up on that, my email's in my profile blurb.)
For those not able to afford a fulltime sys admin that can be a significant expense and bring in unnecessary risk.