Jesus already decided that only men were called to the priesthood when chose the apostles.  He had plenty of women followers, and yet he chose only men for the role of priests.  It is worth noting that Jesus did not even appoint his own mother (who would seem to have been an excellent choice given that she was completely sinless) for this role.  At the end of the day the only reason to be Catholic is if you believe that it is the true faith as ordained by God.  If you believe that the Catholic Church is wrong on this one issue, then why could it not be wrong on others?  What criteria should we use to say that we know better than centuries of the Catholic thinkers?  Why could we not someday decide that Jesus is not really present in communion or that he really didn't rise from the dead?  The role of the Catholic Church is not to provide personal validation for every individual's personal beliefs, it is to preach the truth and bring as many souls to heaven as possible.