The article presents this as general advice and doesn't make any mention of a team size that's appropriate for the recommendations. Maybe this guy has only 1 or 2 developers working on boxes, but IMO for any number of people >1 you don't want shared accounts.
Also you are assuming this servers are staying with the company, which may not be the case
In many cases they will be, and, again, the article presents this as general advice. If a server is being configured for a client and sent out, then a general process of setting up local user accounts probably doesn't make sense anyway (unless you only have one client).
Agreed that LDAP isn't the most friendly of things to set up, but there are how-tos for common use-cases, and if you have any skill as a sysadmin, you can do it. As soon as it's set up, it's simple to maintain. Manually keeping accounts in sync across multiple machines is rarely simple. Maybe LDAP is overkill for a handful of hosts and user accounts, but if you expect to grow even a little, expect to need some kind of centralized user account system.