Specialization is actually one of the wonderful things that fall out of the whole Adam Smith Wealth of Nations Capital system (its why we're not all subsistence farmers). When someone can make something better / faster / stronger then I can, it's a good idea for them to do it and not me.
That bed looks like it might not have been finished and sealed properly, he's definitely not using the green-hued pretreated wood. It'll probably rot by the end of the season.
It's cedar, like the others have said, you should never use pressure treated wood or any type of sealant in a vegetable garden.
I have a cedar raised garden I built 4 years ago. It rains 10 months out of the year here and it's still going strong. No indication of any rot or breaking down.
But your comment is important and shows the power of the internet though. If you went to build a garden, you wouldn't just run out and buy pressure treated wood because you know it lasts more. I'm sure you would take the time to research it at least a little bit on the internet. You'd find this out within the first 10 minutes and then go build yourself a great bed.
A fiction writer, and a fictional character voices it, but seriously, fuck specialization. Sure I'm only a "master" of a couple domains, but familiarity (to the point of competence) in others gives me insight and ideas on how to further my work in my primary and secondary fields of interest/employment.
Adam Smiths point is that you should stick to the production of whatever goods you have inherent comparative advantage at.
That doesn't mean you should be a mono-skilled person with only a bimodal work/consume life.
To be a rounded individual, you need to pick up skills in a lot of different fields, to the point of not being afraid of them. AT the very least, you'll be able to converse to a wide variety of people without feeling like a dumb schmuck.
There is something else going on here. The writer's alternative to DIY was likely a time and resource consuming process of searching multiple stores for a suitable product (and even then probably not exactly right). There is a point where the custom product is easy enough to make and hard enough to find off-the-shelf that DIY is a compelling route even for the timid.
That bed looks like it might not have been finished and sealed properly, he's definitely not using the green-hued pretreated wood. It'll probably rot by the end of the season.