There is a similar question going around, but it just got the same old answers that people always give about Regex syntax, but that's not the point here, so please try to not knee jerk the same old answers about regex syntax. Try to be a little more original and personal about it this time.
Regex syntax is very VERY compact, almost too compact to be good. Its like code-golfing, and everyone agrees code-golfing isn't a good thing in production code. However most people accept regex syntax, which seems... contradictory to say the least.
So now some common defenses one is likely to hear include :
Answer: It's compact
Counter: Haven't we all agreed in this day and age that code should be literate and a variable like "client" is better than "c"?
Answer: It's a "domain specific language"
Counter: how about all the very easy to understand, non compact, non cryptic and dare I say pretty domain languages out there like SQL or LINQ?
Answer: Its easy to understand once you know it.
Counter: Most great languages are easy to understand even if you've never used them before. For example anyone could jump into Python very easily even if they had never seen it before. And why do people defend Regex when its such a hard language to look at, but then go on and complain about Lisps parenthesis?
Ok now everyone try to be original and honest here, don't just pull out the same old rote answers programmers used 20 years ago to design regex. Unless you really believe they are valid propositions in this day and age.
Edit: For the record, I know Regex from years ago, use them frequently even today and might even grok them. However I suddenly had a feeling it was perhaps time to reconsider things I had taken as "truths" about regex, and look at them from a modern standpoint.