xosofiya If it's "equivalent" to TDRC, then use that to "test" builds. Not new gear intended for end game content. As we get closer to newer content - sure, make Yorscalp crowns tradable to prepare for it. But not immediately after release of the content the crowns came in on.
You mention that people would still work for it. Lets look at the TDRC. Once that became tradable, D1/D2 parties practically died and it was nearly impossible to get rep until a few players got involved and started runs to help people get rep again. You pretty much HAD to buy the crown as a new player, And still people pretty much have to buy it because it is difficult to farm for. D2 rep takes for freaking ever to get 2k rep for enchanting it, and it requires 1k D1 rep just to enter D2, which also takes forever and isn't solo-able as a new player.
I disagree with you about weird/niche builds being totally forgotten. I myself am a physical melee cardi. there's like 2 or 3 of us on the server. People want to try different things and you don't need end game gear to try them out.