"Doing things that don't scale" is great advice for people whose first inclination is to automate everything with code, and not do 'people' stuff.
Ultimately, though, you've got to be able to work "on" the business, and not in it, as they say. And that means doing things that "scale" in some sense. If you aim to keep the business small, it means doing things that let you remove yourself from the day-to-day operations of the company.
This is a common misinterpretion IMO of PG's "do things that don't scale" quote. PG is not generally suggesting you should just willy nilly "do things that don't scale" - that would be stupid. He is not generally valuing the concept of unscalable activities.
He is saying "build your initial customer base in any way you can, including in ways that aren't scalable but will get you users, and then treat your first users well in ways that would not be practical if you had thousands of millions of users". That's way I read it anyway.
I see it as how in my first startup, I did phone sales despite being a tech guy, because we had to figure out how to sell our services and wouldn't have known what to tell someone about how to sell them if we didn't. And how all of us took tech support calls because we needed to understand what problems our users had (I learned to troubleshoot Trumpet Winsock setups over the phone "blind" without even once having run the program that way, as we didn't have any Windows machines...) before we could automate things and before we could write better instructions to try to eliminate the problems.
It wasn't that anything we did couldn't be scaled - we eventually outsourced our consumer sales, and wrote detailed installation instructions and automated parts of our setup with scripts - but the easiest way of learning how to do that was to do things in ways that couldn't scale first.
It also helps you recognise potentials for scaling things that potential competitors may take a long time to realise can be scaled, and that they thus may decide to stay away from because of that belief.
I'm deeply asocial, and hates phone calls, but doing phone sales and taking support calls have provided most of the best lessons about customer needs and opportunities I've ever gotten.
Ultimately, though, you've got to be able to work "on" the business, and not in it, as they say. And that means doing things that "scale" in some sense. If you aim to keep the business small, it means doing things that let you remove yourself from the day-to-day operations of the company.