It depends, but if there was a raise preflop or lots of post flop action, then I ALWAYS push this w/ a 56% chance to win. First of all, 56% is great, and you are making money. Second, your not counting the times that the other guy folds here and you take down a sizable pot. You ask why vets give this advice, thats the reason. The alternative is to call the guy down and then fold when you hit air.

Now, if there is little action and a lot of limpers, calling down makes a little more sense. However, if you have a good chance to take down a pot right there and you believe you are ahead, always push!

With respect to this particular hand, you ran into a higher flush. It happens. Next hand.