When you step into a commercial gym it's kind of rare to
see people doing pull-ups and chin-ups.  You'll see people
on the lat pull-down machine, doing cable rows and all
kinds of other machine exercises.  Anything to avoid
setting foot under the pull-up bar.

Have you ever wondered why that is?  

Survey Says:  Because they are hard to do that's why! 

I've got some news for you; if an exercise is difficult to
perform it's going to be super effective.   Don't confuse
physically challenging with technically difficult.  A pull-up is
not exactly an olympic lift that takes months to master.....