I see scripts as one-off sticking-plaster patches.
You should not be relying on them for everyday tasks, or even "every year" tasks, because you're just opening yourself up to problems.
If you use a script on any kind of regular (even if infrequent) basis, you need to get that logic put into whatever system you're performing it against, and get it ratified, and test-suited, and checked, and put into lists of things to keep up to date. Effectively you are then doing software development, whether you're a tiny one-man operation or a huge multi-national, and the same standards as you'd expect a software developer to use should apply - testing, verification, dummy-runs, early bail-outs, stop on every error, etc.
If you're using a script for a one-off action, on your own head be it. At the very least, you test against copies of the production data first, but even if you spot nothing it doesn't mean you haven't broken anything.
Any idiot who just codes up a script and executes it should be fired. At the very least, even as a network admin coding up a "replace all job titles" AD Powershell script or similar, you replace the dangerous parts with a print statement along the lines of "This would remove user X" rather than actually modify the data.
I think of this every time I'm forced back to Powershell / Exchange Management Shell to do simple actions like search for a particular email, etc. Check you have backups, do a dummy run, be careful of any command that actually performs an action until you've tested the action itself on one test user, and got a list of users that it would try to apply it to, etc.
And if you have an ounce of common sense, any action that "takes out the entire AD" shouldn't even be executed as a user with permissions to do anything like that... you test as a delegated admin with almost no rights except to the fields you're modified because then if the script "goes rogue" it can't shoot off any bits that you weren't going to be playing with anyway.
Playing fast and loose with your business / customer's data is a sure way to end up on the dole queue or in court.