Deej and the team seem to have no idea how to make players happy.
It should be obvious that their system effectively tells players, "All that time you spent on the ridiculous grind to make your exotics useful was completely wasted, you should've just archived your exotics until the expansion hit. By the way, another expansion hits in a few months, so what's the point in grinding up your Suros AGAIN?".
Reforging gets you a 7% damage boost against enemies at L21 and a 11% damage bonus on any enemies >L21. Just to put all that grind into perspective.
The solution is simple. You just patch the exotics to have new upgrade bubbles at the end of the tree, which require the use of the fancy new materials. Everyone is happy. Players still have lots more grind to do, but it doesn't just eradicate their previous progress.
If Bungie are still worried about players not having enough grind, then instead of all this hoop-jumping reforging bollocks, Xur can just sell an exotic facepalm emote for 1,000,000 experience, 23 coins, 24 ascended energy, 2 exotic energy, 10,000 glimmer and 120 relic iron.
I think they looked at how some masochists like the CoD prestige-reset model, and thought it would be a good fit.