His post is right in that he says you outsource things that don't give you a competitive advantage. But this is not necessarily synonymous with things you don't care about.

For example, our company has an email newsletter we sell for which we evaluated multiple email service providers (ESPs) and ultimately agreed Mailchimp was best. This newsletter is a major source of revenue for us so we absolutely care about it, but we know that the value we bring is the content/data in the newsletter and not the delivery and other intricacies ESPs deal with.

Ensuring the team gets paid regularly and we're not running afoul of the IRS and NYS withholding requirements is absolutely critical, but building payroll processing capabilities internally is not something we're spending time on.