I think you are not figuring it simply.
On the flop you have 2 cards to come if you stay in the hand. If you flop 4 flushed, using your example, you are getting 4-1 odds to call the $2 bet. After you call the pot will be 5x your call, but you can't (or shouldn't) add your call into the pot odds before you make the call. The call should stand on its own merits.
Incidentally, without getting picky and splitting percentages, you can use that same 4-1 number if you flop an open ended straight draw, or a set hoping for a boat. Yes they are not exact.
The odds on completing any drawing hand are complicated when you watch TV because the TV editors computer has taken into consideration all the cards seen so far, including mucked hands. So for purposes of quick mental calculations I have found it simple to assume a flat deal, meaning the suits were spread even. In a 9 handed game with 18 cards dealt, 4.5 hearts were dealt (beware the broken hearts, they tend to drive Toyota 4-runners).
I usually equate the possibility of another player having a better 2 suit holding in my suit about equivalent to the bluffing possibilities inherent in a 2 suited flop. You've seen it often enuf, we all have, some folks see a 2 suited flop as a great opportunity to represent the flush draw. And even if they flopped a set, they will play it as if it was the draw. Draws tend to make big pots.
These odds are not actually correct, and there are many folk who could recite them to 3 digits, but all 3 draws are close and the 4-1 odds makes it easy to lump them together. This reply also mentions nothing about implied odds. Implied odds take into account future actions. What can you expect villain to do, or the other 3 players in the pot?
Remember that when you call a pot odds situation, you change the odds for anyone sitting behind you.