Just remember.
...that poeple have know that windows has been and still is full of holes and that constant vigilence and a raft of security procedures are required to "Harden" Windows sufficiently to prevent Trojans, Viruses, Malware etc. But there are still people out there who dont protect their data or computers...
Why? lots of reasons, ignorance, apethy, arogance or lack of skills.
How could you possibly think that the same does not apply to business?
For along time SCADA networks have been safe because they were isolated. But with in implementation of new business pratices, new markets and changes to "Core focuses" a lot are now being connected up to Corporate Networks.
New technologies such as Wireless Broadband, wifi and VPN are being introduced to enable the "Valuable" Data that SCADA Systems hold to mined and utilized. Or to even centralize control to allow downsizing, you name it, they have all been used as excuses.
Unfortunately, like in any business, security always comes last or never at all. Or more likely when the business is hurt by a breach in it.
What can I say? Dont think for one minute that the idea of using the SCADA as a reasource for business automatically means they will use the right level of security when connecting it to their corporate networks. If you do you are living in a dream world.