Sure, we met those deadlines, we implemented those features and we made small fortunes for the company. But at what cost? The infrastructure starts to resemble Jenga more and more, your spaghetti code becomes harder to maintain, you end up with magic strings, magic numbers, client specific cases and conditions and your start eating into your IT budget by having to hire more programmers to support all of your crappy implementations and more hardware to handle the un-optimized pile of crap you're running.
What's worse is the very people you rely on to keep this tower from falling over, your programmers who have become so familiar with all the undocumented edge cases of your system, are also the very people you're basically forcing out. You're forcing them out because they become tired of not innovating, not refactoring and not progressing the technology OR the business, but instead spending all their time stressing over not "crossing the wires" of this delicate catastrophe. And when you finally lose them as a developer, and you will, it costs you severely in down-time and loses in productivity while you get your other developers and new hires up to speed. But not only do they have to learn the business, they also have to learn all the edge cases that were only known to your senior employee who was finally fed up and quit. And guaranteed, something, somewhere will be forgotten, that wire will get crossed and you'll pay dearly.
And while I do agree that making money and growing the business is the end goal of the business, don't assume that your IT guy isn't concerned with that and just wants to write "pretty code". Often times your IT guys understand the business more than sales, middle management and sometimes upper management because they deal with the logic, the clients, the sales team, and everyone in between day in and day out. When they're pleading with you to say "no" to a customer or ask for an extension to implement feature "x" properly, maybe you should take heed a little more often. Because the duct taped feature "x" that won over client "A" today, could be the same feature that loses you client "b" and "c" tomorrow because the only developer that new their system well enough to keep them running walked out after being forced to write yet another band-aid.
Of course when he quits and everything falls apart, everyone will just assume he was an overpaid, crappy programmer and his buggy code is what was the ultimate cause.