I believe this saying gets misused a lot in poker. Let's really think of this in a logical way. If a table of players followed this rule, then the only things people would be doing is raising and folding. So, either every hand would get it all-in preflop (the result of always raising and never calling), or there would never be a flop as the only other option is to fold and not call. So, clearly, this "rule" is either getting misused or misunderstood.
So, the question is where did the rule come from. Well, I did a Google search and found a reference to it in the movie Rounders. I also found a book titled "The Everything Poker Strategy Book" by John Wenzel that used it in reference to Tight Aggressive players deciding if they are going to enter a hand pre-flop. On an 888 how to page it specifically uses the phrase in relation to opening the pre-flop betting. Which would make sense preflop, if the bet to you is low and the pot is low, then yeah, throw a bet out instead of calling if you are playing TAG.
Granted all that is is a quick Google search, but I think we can rule out using this as a rule for every situation. Things like someone post-flop betting half the pot at you when you're on a monster draw would require a call for a chance to see the remaining cards.