Any pianist that aims for a professional career should make sure he's got a very good technique. Anything less than that is pure amateurism (like me for example...). It's like the architect saying that it doesn't matter what quality of material he's using for the house as long as it looks good... The technique is the one that allows you to express anything you got inside.
Now, anyone speaking against Horowitz is gonna be in deep trouble with me. All technique, zero music ? Well, his interpretations of many coomposers are among the best, with a lot of imagination, colorful shadings, emotional range. How ? Through his fabulous technique, for without it he wouldn't be able to be Horowitz. When you put a CD on, ther is no way to miss that he is playing. Not because it is technically perfect (he actually used to make wrong notes in different places), but because the way he expresses the music is highly recognizable.
Horowitz, by the way, did not play only brilliant virtuoso pieces. As encores, he could play a Chopin etude as well as a Mendelsohnn romance, a Rachmaninov transcription as well as a Debussy prelude. And that bang on the piano that some apparently don't like, it is just an unlimited expression of the mood of the piece. Music reflects our emotions : if Chopin Ballade in G m has a ff on a chord to express desesperation, why should we feel we need to balance that ff ? Cause it is too much ? Cause it is going to scare the little old lady in the first row ? I guess that in this case none of us should play Albéniz, with its ppppp and ffff...