That would mean high quality posts from legendaries wouldnt be marked as such, which destroys one of the purposes of publicly showing merited posts, giving good examples.
Also, when you send merit to a legendary, they gain 50% as sMerit, thus giving them an additional balance to be distributed.

Simple example: I have 50 sMerit, I can't read the forum right now and distribute them, but you are writing really good posts, I reward them to you for one of your outstanding posts,
now you get 25 sMerit, you do read the forum, select high quality posts from lower members, and contribute to the distribution that way.
The difference here being either 50 in my account and dormant/lost or 25 being actively distributed and rewarded. The latter should be the option to pick, imo.