I just think alot of people put baseball in this vacuum and assume team management is universal for all the major sports. While a cap works in most sports, you have two main ways of winning in baseball. 1)Free Agents and keeping talent away from competition. 2) The farm system.. You have alot more options and control over young players in MLB, if you lose a FA (type A or B) you get compensatory picks , work in cheap veterans and reliable utility players and you have yourself a competitive team.
I wouldn't have a problem with a cap, i just don't think the system in place right now is as broke as alot make it out to be. Hiring a competent front office and a good scouting staff trumps any overinflated John Lackey deals.