Mixing breeds makes for a lovely, colorful flock!
Not so great for breeding programs, though.
I actually WANTED to get all different breeds, because this was my first foray into keeping chickens. I knew I'd name 'em, but if they were all RIRs, for example, how would I tell them apart? "Good morning, Rhoda. And Rhoda, and Rhoda, oh, and Rhoda. Good morning to YOU too, Rhoda! 'Morning, Rhoda. And Rhoda!"
A couple of months ago, I bought two Golden Lakenvelders from a BYCer, and worried about telling them apart. But I learned how to do that, so now I have four more chicks in the brooder and two of them are Welsummers. I can tell Laverne from Shirley and expect to be able to tell 'em apart once they are fully feathered, too.
The other two chicks are a RIR (finally, a Rhoda!) and a Plymouth Rock Barred (Betsy).
Once they make it outside to their own coop, I'll add their particulars to my signature.