At the lower levels, pushing is often over-used, but at the higher levels, many underestimate their value. All top players have excellent pushes. However, advanced players - and even intermediate players - rarely push against deep backspin to the forehand, unless they are choppers. (And even choppers will often attack them.) It's simply better for them to attack, usually with a loop. (The same can be said on the backhand, if you have a good backhand loop.) So … should you develop your forehand push?
The answer is yes - but not necessarily against long backspin to the forehand. You need to develop your forehand push mostly against short backspin to the forehand. Against this ball, you can attack, but pushing is often the better bet. You can push short, push quick and long, go for angles, heavy spin, etc. - all sorts of variations. And because you are closer to your opponent, he has less time to react. (At the same time, don't predictably push - learn to flip short balls as well.)
The problem is how do you practice your forehand push? If you push forehand to forehand with a partner, then unless both of you are practicing short pushes, you'll be practicing pushing against long balls. The answer is to develop the forehand push this way with a partner, but once it becomes relatively advanced, start focusing on drills where you start the drill by pushing against a short backspin, and then continue the drill/rally with other shots. You won't get as much repetitive practice this way, but you'll practice what you need to develop. For example, your partner serves short to your forehand; you push quick off the bounce to your partner's backhand; he pushes quick to your backhand; and you loop, either forehand or backhand. (Or, alternately, your partner loops off your forehand push, if it's "his" drill - and you still get practice pushing!)
Meanwhile, a nice drill is to push forehand to forehand (or backhand to backhand) where both players push short - but the first time a player pushes long (by mistake), you loop. This develops your short push, develops your loop, and best of all, it develops your judgment on whether a ball is long or short.