Today, technology is not only changing so fast, but it is becoming pervasive and specialized. We have come a long ways from Novell networking and Windows 95. Today, a Cisco certificate or a Microsoft MCSE doesn't begin to cover all of the subjects that the IT department has to handle. Not just Linux and Apple O/S, but how many versions of Windows do you have to support - XP, Vista, 7, 8, and 8.1. What about the mobile versions - Android, Blackberry, Apple? How about securing these gadgets - laptops, smartphones and tablets - from malware or connecting them securely to wi-fi networks?
In networking, it isn't just a Cisco switch or router, there are firewalls, VPNs, even the VLANs for MPLS that have to be configured, managed, updated and monitored. This on top of the servers and desktops.
What about data backup? Who is handling and checking that?
Email is a topic unto itself. Cloud apps have to be handled.
UC - whether it is Lync, Cisco HUCS or a cloud UC platform - has to be managed, supported, and MAC/Ds taken care of. Add in mobile UC apps and IP handsets the plot just thickens.
I have been on calls with network engineers who struggle with MPLS, Internet and VoIP convergence. (To be fair, every carrier handles it differently and sometimes the carrier isn't that clear either.)
Beyond supporting users, their gear and the software, the IT department has to run the LANs and WANs and the data center, which now involves public and private cloud infrastructures. This gets the skill level of the IT department rather quickly, don't you think?
Hence, why cloud software and managed services are on the rise. Companies, especially smaller ones, don't have the skills or personnel to handle the numerous responsibilities that fall onto the IT department. We've come a long way from a few desktops, a printer and a simple hub.