Right. The phenomenon is real, but the description on that site seems a bit obtuse on purpose:
> For organizations with more than a handful of employees, this feature is critical for IT and Security teams (...) In short: SSO is a core security requirement for any company with more than five employees.
No, it isn't. They'd like it very much, but the SSO tax is proof positive that this is not a truly critical feature for small customers. In fact, it pretty much measures at which point it becomes critical.