Yes, because the way businesses work sucks.
Look I'm all for agile so long as businesses suck, but businesses should not behave in such an insane manner.
Agile
The regex worked, it was just stricter than it needed to be. It didn't cover some valid email formats.
They didn't care.
Benefit of the doubt, they had some legal or security reason to use exactly that regex. If your requirement was "implement email sanitization using this regex" then that's what you do. You don't bitch because the regex doesn't work with @cock.li emails or something.
Agile gets a really bad rep since it became a buzzword that long-nose salesmen throw around like it's the philosopher's stone, and as other user have said, it will not work if the company works on a waterfall model all around while only the dev team tries agile.
From my work experience, if the dev team actually manages to take a hold of the production cycle of the company, and the other areas get used to the sprint cycle, you actually can get some work done.
Also, if your sprint doesn't focus on actually finishing a product that can and will be used as soon as possible, even if it means to do shit manually so it works, the client will just keep adding shit to the backlog pile and you'll never finish anything.
Too much management is fucking poison, the best environment in my experience is the end user telling the dev team what his problem is, no architects, no project managers. If you keep adding barriers between the end user and the dev team you'll suffer from "why are we implementing this?" "I don't know, someone said it was important".
At most you need someone whose work is to tell the other areas of the company to fuck off because we have too much work, most of the times this should be the product owner/scrum master or just someone that's more experienced and has a smaller chance of being fired.
Some of the symptoms associated with Scrum that are bad:
I like the idea of the Scrum master if they can keep the suits/biz folks at bay while managing the project a bit more impartially. Flexibility and less FUD about trying a new piece of technology is also good to an extent. The sprint cycle is really a customer based/assumption of ever changing goal thing, if your project doesn't meet this sort of description it might not really see any benefit from these sprints. Generally, the industry is way too excited about Agile for their own good.