There's Rewards for partaking in content, and there's rewards for being forced to partake content.
And then there's Rewards for being forced to take part in the content in a limited time window where only a few people will actually get a chance at obtaining it. Most of which are alts, WinTraders, and minority of actually determined players who earned it.
Nothing wrong with the Rewards being only obtainable from Trophy Crystals and Wolfmarks.
It's just an extra bonus for partaking in PVP.
As with all Content and Gamemodes, The Main Priority of it, is to be fun, or enticing enough for those who like winning against other players. (Which for the more extreme of those players, the title and Seasonal Numbers is the Memory that counts. <though personally, I would change the seasonal number to how many times you've reached a tier, rather than the season you won. That way those with a Higher Tier Number would be more impressive than just a clone copy for having reached a tier during a time of play.> XIV Platinum/Diamond/Crystal Tiers is much more impressive that simply reaching that tier during Season XIV)
But back to Rewards, I see no reason for it to be tradeable or sellable.
All it does is incentivize those see the game as a marketboard minigame, It isn't.
Just like Certain new content will have issues when it dries out.
The focus should be on the content and the enjoyment. and The Rewards should match the content as well.
Feast/T100 is better off dead in the past.