Rare items are definitely needed. Gathering is fast becoming worthless as markets are flooded with the over-supply of materials that the game is currently producing. I'm all for cutting supply such as limiting all logs to be one per gather, same with ores and fish. But additionally we need those rare ores and logs that you might only obtain on average once per 10 hours of gathering time. They will always be valuable as long as the finished items are useful.
Sitting on my retainer rotting away along with every other +2 or +3 gathered item that I have not crafted myself. People expect these +3 mahogany logs etc. for the same price as NQs and refuse to pay what they're worth, therefore I'm not retarded enough to cave in and sell to these people.
I've made two Vintage Kite Shield +2s and neither time did I need +3 mahogany or siltstone. Twice I have crafted +3 mahogany lumber rather quickly with NQ logs. Of course this is why people won't pay extra for HQ logs but you still aren't getting mine at NQ prices. Those people selling their +3 logs and ores for NQ prices will be kicking themselves when tweaks are made to the crafting system.
Currently teasing people on my server with +3 mahogany branches at 100k gil each for their Barbarians Bardiches. They either pay what they're worth or they can farm their own and I'll use them some day when I can profit off them myself. These things don't grow on trees. Oh wait...