Sure, of course he can and should be taken seriously as an artist. But just ask yourself, if you were sitting down to write an essay about "That Joke Isn't Funny Anymore" or "You Have Killed Me", could you really explain the power of either song without addressing the guitar, bass, and drums? Even if you argued that Morrissey was 80% of the reason the songs worked, you couldn't get away from the backing music, or (as I said above) any of the other peripheral elements.
True. Troy Tate Smiths recordings and Jack the Ripper springs to mind... As a song the impact of the lyrics and their meaning for me was diminished byt hte under par original.
However, the lyrics come alive with the better sound of the subsequent later and live versions.
He is a great Emotive singer, perhaps one of the best ever. However, most of his songs do not make the best poetry when read (not sung aloud)... Some do... this charming man;s opening lines are excellent poetry -
Punctured Bicycle,
On a hill side desolate,
Will nature make a man of me yet?
However, continue to read it as poetry and it loses its way. As a song it conitues to be marvellous.
This is especially true of songs with reptative choruses.
Poetry by definition is an expression of awareness through meaning, sound, and rhythmic language.
Morrissey's is at best an average poet by this defintion however, a great musical artist.