No, you said you believed Rhodey should have a stronger voice.
At no point did you say his acting was shit.

You had a a fan boy perception of what his voice should be like, and you felt let down because it didnt live up to that.

Now as for your Dirty Harry comparison, it just doesnt work.
Before anyone watched the movie, they had no preconceptions of what Harry should or shouldnt sound like, other than the fact Clint will sound like Clint as they knew it was a Clint film.
Now if Lynde had been initially cast, people would
1) expect a Paul Lynde film
2) expect Paul Lynde to sound like Paul Lynde

Now if Clint had come on screen and didnt sound like Clint, then maybe people would be put off.

Granted, if Wolverine in the X-Men sounded like an Australian, then you might have something to complain about.
Or if Batman spoke with a Welsh accent, then that would also be something people could have a genuine gripe about.
But the tonality of someones voice (unless its totally annoying like Pee Wee Herman or Bobcat Goldthwaite), should not enter into the debate if the acting is not a problem.

As has been said, if you go look at all the people in your military services, I am betting they dont all have the same cliched macho voice no matter how tough they are!