I write my own scripts, and do programming for others as well.
The problem with scripts is that no matter how much support you give, there's always gonna be some lame idiot that fucks up regardless, and there's always gonna be some whiny bitch that keeps complaining as long as the site doesn't run itself completely and doesn't get at least 25 million hits a day.
Example: I wrote a custom script for some guy, he said he knew a lot about computers and software and such, so there was no need for me to make it very userfriendly. I finish it, a day later he contacts me and says it isn't working. After a LONG time of searching, I finally find out that the moron has been messing with the insides of the script, and somewhere replaced the value of a variable (without any apparent reason whatsoever) with "thirty", not "30", but "thirty".
(edit: and yes, the script was expecting an integer there)
Example #2: Some guy had me custom make a small toplist script. I made it, finished it, it did it's job perfectly. Next thing you know, he starts complaining... because the bloody thing doesn't have a "TGP function"!
The bloody idiot actually had the nerve to offer me $25 (yes, 25 USD) for adding that tgp "function" - in his opinion, a simple matter of adding some minor details, like a gallery-checking bot, automatic thumbnail creation, support for submitter accounts, and some other "small things".