Those chilly mornings are hell on my knees and tights are the only way to go. Pants just don't cut it for me. If I'm going along at any speed, the whipping of clothing against my skin is very irritating so if I wear something other than cycling clothing, it has to be very snug fitting. If I'm just riding to the corner store, then it doesn't matter what I'm wearing but if I'm commuting or going for a ride then comfort comes first. However, everyone has their own comfort level so wear what works for you and disregard those who disagree with you.