Why are Dublin Airport taxi drivers so annoyed when I ask them to drive me 10km away?

I live exactly 10km away from Dublin Airport by car and whenever I get in a taxi at the taxi ramp and ask them to drive me down home they always sound super offended like I just killed their whole family or something. One day your man got so pissed off I told him to stop and drop me off before even leaving the airport so I could catch a ride with someone else. He said he doesn't want to give bad luck to someone else. It usually cost me 25/30 quid for a 20 min ride which is more than majority of people make per hour. What's up with this attitude? Is 10km really that short of a ride in taxi terms? Maybe there are better ways of getting a taxi at the departure ramp?

EDIT: Wow guys I did not expect this to blow up so much. Thank you all for all the inputs and thoughts. It appears it is a common "problem" not just for me and reading up it appears plenty of people experience this. I can see why they would be frustrated due to a system that does not seem to be fit for purpose anymore but at the same time abusing customers is not cool. It is not like if I have a bad day at work I go ahead and start abusing my coworkers or clients. Thank you all again for your inputs!