Why does Reply All also reply to me?
A coworker pointed out an inconsistency with my email account and that led to the resolution of the issue.  

On our corporate server, there is a main email address and you could also make any number of aliases.  So for instance, my email address is frankrizzo@mycompany.com.  But if you send me an email to frank.rizzo@mycompany.com or frank+rizzo@mycompany.com, it will reach me as well.

In the iPhone, I entered my account as frank.rizzo@mycompany.com (with the dot).  However, people kept sending emails to my main account - frankrizzo@mycompany.com - without the dot.  The iPhone saw the one without the dot as not mine and thus was including it on the Reply All screen.