Why we cant use word "premium" in our theme's title as it's part of our theme's proper name?

We cerated a Bas*** family of themes and “Bas*** Premium” is a main theme and next we’ll provide a “Bas*** Basic” theme. In our case words as “premium” or “basic” - it’s a part of our theme’s naming philosophy. Why reviewer soft-rejected us and asked to remove the word “premium” from our item’s title?
In TF rules this word is not prohibited also, it says: “Do not use subjective words like brilliant, amazing, or best.” So, can we use word “premium” other authors already use it? Just type word “premium” in TF WordPress search field and you’ll see hundreds of items with this word!

I think that’s because all the themes on themeforest are premium. themeforest sell premium themes so that’s why they dont want this word to be used with a specific theme.