That's odd...
You didn't test it by clicking Bruno did you? His cape makes him invincible to bans, so no ban button appears for him.
I logged in as testdude (my test account with regular user permissions; the button still shows up when I view profiles)
I wish it wasn't there, but we have no control over it - it's the people that make Tapatalk.
Btw, running the most recent version of the software on a Motorola DroidX.
It's possible that the iphone and android versions of the software are different.