Well, why would you sell your items just to hoard Gralats? I want to sell items to save space and for quick money when you're poor.
We all know, There are tons of players that would definitely find a way to hoard the gralats. Not being able to sell trade-able items would limit this issue.
The message I commented earlier was more of a response of Vaki's post on the profits.
2012-2015
"The Pessimist complains about the wind;
The Optimist expects it to change;
The Realist Adjusts the sails."
William A. Ward