I don't think cardio is bullshit ( although I used to think that ) but you do have to put it into perspective.
It isn't the be all and end all of loseing body fat , it is meant to be used as part of a quality weight training plan and diet. Your right that a cardio session can burn 200calories which isn't very much but look at the big picture:
When I prepare for a competition I used to do almost no cardio because I didn't see much benifit in it and the risk of loseing muscle was higher so I realied on my diet. I found that I did get good results but in the long run the results and the diet would be better if I did cardio. For example , I will do 2 cardio sessions a day for 5 days a week that will burn approx. 200 calories per session. I do carido either first thing in the morning or after a workout because that is when your glycegen is at it's lowest and if the cardio is of low intensity you will use stored body fat as energy. This means that in one month of cardio I will have the following result:
200 calories X 2 per day X 5 days a week X 4 weeks = 8000calories
At 190lbs I would lose approx. 1.25% bodyfat in that one month.
Now 1.25% isn't much but on top of weight training 4 times a week and eating strict 5-6 says a week that can mean a total loss of 4% bodyfat in that month ( which is noticeable ).
If you train and diet well with this cardio plan for 3 months the cardio alone can burn almost 4% bodyfat on top of the bodyfat you lost from the diet.
What this all means is that it does help lose bodyfat but I agree it isn't the most important thing. What people don't realize is that weight training burns alot more calories and 30minutes on the treadmill. A 45min intense weight training session can burn 600-700 calories at a bodyweight of 190 which is the equivilent to 1 hour of cardio.
For me the diet is what causes the greatest loss in bodyfat , weight training second , and cardio third. However all three together can maximize the body fat reduction in a given period of time.
The only other reason for cardio is for overall cardiovasculer health and to increase endurance.