true, but by flat calling, we allow ourselves to get away from it when we miss, but then also have implied odds after we hit. As you cant put a guess on what implied odds you will be getting, you have to put out an estimate. So lets say after hitting our flush we will get another 50$ from 1 of the villains, seems reasonable.
Therefore, we are getting 5:1 on our money to call the initial bet making it profitable to call that in the long run. But if we include implied odds, we can change that value to about 7:1. Meaning we only have to hit once in every 7 to make a profit. Law of averages say that we will hit our draw at least once.
I hope that makes sense. Also, im not really sure if it completes the arguement about which is most profitable, but if it doesnt, its a pretty good article about why pot odds
nad implied odds are profitable
Edit: Please dont limp with k,2 suited if the above situation is based on a real event