Good grief, you're really stretching to find excuses to be negative. You're judging Miller because of his name?!
What in the seven hells of Mongo has that got to do with his ability as an actor or suitability for a role? Perhaps you're unaware that Jonny Lee Miller and Benedict Cumberbatch co-starred in a two-man stage version of Frankenstein
in 2011 -- and each night they alternated
the roles of Frankenstein and his monster. That production was well-received, and proves that the two men are more than capable of playing the same character. (Though it's pure coincidence that they both ended up playing modernized versions of Holmes.)
I'm quite enjoying Elementary
. Sure, it's Sherlock Holmes as a modern American crime procedural, but as American crime procedurals go, it's nicely Holmes-esque, with very clever, convoluted mysteries and good character interplay between Holmes and Watson. I like Miller as Holmes; he's definitely playing a younger, softer version of the character, but there's nothing wrong with exploring variations on a theme. Heck, that's the whole reason we have different actors play the same role -- to see what new angles they can find, what new approaches they can bring to the interpretation of a character. How boring it would be if every writer, director, and actor approached Holmes and Watson the same way.
And I've got no problem with Lucy Liu as Watson. I'm enjoying the way her character is written -- the way Holmes has made it a project to cultivate her deductive skills, and the way she's allowed to be an important participant in the cases rather than just the person who needs things explained. (The one big thing that's missing from this Watson is that she's not chronicling Holmes's adventures for publication.) And Gregson's friendship with Holmes is an interesting addition to the dynamic -- a bit revisionist, yes, but reasonable in the context of the show's premise, since Holmes is in New York and would need someone local to anchor him and support his work as a detective.
Oh, and another cool thing about Elementary
-- it has an actual honest-to-gosh main title sequence with theme music and credits and everything, as well as a clever visual design. It gives me hope that those are starting to come back in style.