For me, the whole point of baking a sugar cookie verses a chocolate chip, oatmeal, etc... is that, it IS bland. I include it on sweets tables for the fussy eaters and kids who want to eat something pretty, but plain. I make macaroons and tons of other options for the people who like good baking.
But I do agree about punching up the flavor if it's served as a stand alone. Don't forget oils, like lemon, orange, peppermint work really well in flavoring cookies in addition to your standard extracts.