Of course, take powder when you to get it. I'm really glad I do both though because it keeps you satisfied no matter what the day, and when all the powder is tracked out, the park is a great option. I'm not one of those people that's going to ski in the trees all day looking for some powder after the snow storm.
I know a few people who will only go skiing if there's snow, the rest of the time they just sit at home and smoke pot and watch tv/play video games. Sucks for them that they don't diversify their skiing