It is really just another set of tradeoffs and I think the author does a good job of detailing them from the perspective of company with internal customers. With external customers, the calculus can change.
> But ultimately it will kill you, and the longer you do it, the harder it is to get back onto the path of righteousness - a decent multi-tenant architecture.
Hahah!
The nice thing about a multi-tenant architecture is that it enforces consistency and therefore gives you scale. This can be achieved with single tenant as long as you are ruthless about it (that's what we have done at my current job).
We run separate servers for each client (they can also self host). We built a system to let clients control their version, so they can stay at an earlier release. But everyone stays on the mainline codebase and, critically, database schema.
But sticking with a multi-tenant architecture for a publicly facing application will make it easier to enforce that consistency. That may lose you some sales, but will lead to better scalability.