"wicked good"

http://pressherald.mainetoday.com/news/local/060625soupkitchen.shtml

"Being homeless this past year has been very trying," he said. "These people have been wicked good to me."

My grandmother always hated this phrase, considered it a contradiction in terms. How could something be both wicked AND good?

But we really do say "wicked good" where I come from.

Evelyn