It most certainly IS a steak. Considering the definition in most dictionaries just calls for essentially "a piece of meat" it most certainly qualifies.
Let said person be unaware of the bliss that can be had with a flank or skirt steak for more than half the price of their "Filet Mignon Fajitas"
Every cut of meat has its purpose and culinary strength. Your friend's just an idiot... He'll probably just put 57 on it anyways. Relax.
That's like people that come to your house for a cookout and throw a fit when the steak you give them isn't cooked to their exact temp. I'm a restaurant worker-slave and have spent my fair share of time on the grill (and I like to think that I know what I'm doing), so one person's eccentric behavior usually gets them a pre-printed google map with directions to the nearest steakhouse (where they've most likely sent a few steaks back that they were actually PAYING for, probably just as unwarranted) Usually it's taken well, a little joke between friends, but once it caused a rift which I really don't regret because who really ends a friendship because his wife's steak was undercooked? (I really can't make this up, the kicker was it was at my house and I bought ALL the groceries.)
For the record, I always order med-rare, but I have had an exceptional steak that was just about medium-well maybe even above it, and a wretched one that was cooked to the exact temp.