I once encountered an actual real live business application that included a web server written in VB6....

The only sucky things about VB6 was threading wasn't a regular language feature. You could get to it through the WinAPI but that's not organic enough for most VB programmers. One thing I do miss about VB6 is that you didn't need an entire runtime to build a GUI.

I wouldn’t say that was the only thing...error handling was a mess and I don’t even want to remember what I had to do to make a hash table - there were definitely low level calls to RtlMoveMemory and such.

I can see how that would go; I mean "how to serve static files" is one of the first things that you can learn when doing e.g. NodeJS.

I never did find out the real reason - I suspect (as it was a relatively small business that had been acquired) that it was because they were too cheap to pay for a server edition of Windows.