There are other ways to get shards too. Fractals, orrian jewelry boxes and laurels for example.
I think the dude just made a point that they should NOT be left to those instances only, but implemented in other temple vendors, REASON solely being that some people are building up karma to spend on it but are not able to since it is ONLY limited to Balthazar vendor, and Balthazar is hardly ever uncontested.
Please do read carefully what he was trying to say before actually trying to point out the same points that he already made, said points being unfavorable. He did not say he does not know of them. He said they are unfavorable.