I thought that the clones will be used by enemies of the Republic/Jedi Order, together with droid armies. Making clones to be "the guys on the good side" somehow ruined that "eerie" premise of a dark & brutal war. Clones in other sci-fi works are often treated as sub-humans, so when teamed with robots (or better: bound with them, in cybernetic organisms) it would give the enemies of the Republic an "inhuman" look&feel...

Now they're "cheap stormtrooper army".

Did you noticed how ROTS finally destroyed the "menacing" image of the droid army? It was already rather weak ("roger, roger" lol) and the AATs were no match to the awe-inspiring Imperial AT-ATs. But the remaining "bad-ass" design, the Battle Droid, are now turned in some silly metal cans. Only the Droideka (Destroyer Droid) retained its coolness.

This was all planned by GL - after all, TPM should not be too "scary" or it would scare away the kids... go figure...