SQL server has become such a robust compliment of tools that it is hard to say exactly what a SQL server DBA really is. I don't think the author was denying that, but simply stating that before posting, employers should assess their needs - and determine the type of DBA they need.
I've recently been pushed to my max trying to develop an ETL process in SSIS. And I'm realizing that SSIS could be a speciality by itself - you could hire an ETL DBA that may never run a backup script - ever! Same goes for SSAS, SSRS ... But I think the point still stands that employers try too hard to find the perfect jack of all trades. I saw a DBA posting today asking for 5 yrs of Exchange administration, web programming, VLAN admin, IDS, C#... If you hired a DBA and set them to do hefty Exchange administration and intrusion detection, their DBA skills would deteriorate within a year as they are forced to implement email filters...