I am guilty of that... I have downloaded apps only to decide they were worthless and removed them. Either it works and I use it, or I remove it.
Free or $1 or $2 makes it less risky to see if something will work. It is worth $1 to me to see if something solves a problem, I would not risk $50 for a software program.
I suspect first time mobile users treat 90%+ of the apps like that: run 1-2 times and uninstall.
It's with your second, third device (smartphone or tablet) the excitement fades away.
But switching platforms brings it back at least partially...