Anybody who has worked in any kind of customer service or public service type of job would know that people say the same stuff, make the same queries, the same complaints and react in the same way to alot of stuff.
Not just at work. If you live with people you should be seeing alot of repetitive stuff going on. Perhaps even YOU are repetitive when it comes to telling people to do or not to do certain things at certain times...
So they put it in the game too, what's the big deal? What are people expecting? You want each NPC to have 5 hours worth of dialogue? Thats just not realistic.


