Why was Ben Roethlisberger drafted so high despite playing college football for a school in a weaker confrence?

I know Miami - Ohio has a generally decent football program but the comp they play against are usually weak compared to bigger schools and conferences. Did the school he play at make him be viewed differently compared to if he went to bigger school? I know Ben is still one the best QBs ever I was just curious and I am only 23 so go easy on me.