Because tricks mostly don't last. And then you're stuck with a weird behavior you've developed. If you block, when you were younger and got stuck on a sound you probably pushed a little to get it out. Eventually you had to push harder and harder and I'm willing to bet pushing eventually stopped working but you still do it anyway. That original push was a trick you learned to get get the word out. Tricks are bad because they are unproductive speech behaviors that add more junk to your speech.