People like you are the bane of my existence... when your undocumented, unsupportable [bleep] is causing *my team* to field support calls at 2 AM on a Sunday morning.
That's a common problem. "Semi" IT people "in the field" get something practical up and going, but it's a potentially huge maintenance headache down the road.
The snag is that the "central" IT office usually doesn't have the resources to "do it right" from the start. They get more requests than they can handle, in part because many requests are bogus, but it takes analysis to know that.
And when the rogue app breaks, SOMEBODY has to try to fix it, and that somebody is often the central IT people when the lone-wolf builder is on vacation or leaves the org.
But one advantage of this is that the lone-wolf builder has the domain knowledge and direct contacts to make the customers/user happy, at least while it all works. They are doing much of the analysis, prototyping work, and proof of concept. If and when a formal project is started, much of the domain-study foot-work is already done.
One guy at our org cranked out bunches of apps in MS-Access that users loved. But he retired, and database file corruption issues and lack of documentation created problems for those trying to fill his shoes. However, his apps road-tested his concepts and many were ported to formal apps when the time came.
The "panic fixes", like your 2am call is still a friggen bummer, though. I don't know of a good solution. Perhaps a compromise can be made whereby the lone-wolf dev is required BY POLICY to answer a series of questions about support and do basic documentation. The questions and requirements may also encourage them to consider maintenance issues. Example questions:
Is this project critical to the organization?
What are likely problems if it stops functioning correctly?
Are you the only one who knows how to fix it?
Is there a "manual" alternative procedure in case the automated one fails?
Is there app documentation? If so, where?
Are there regular backups of the software and data? If so, where?