I completely agree with OP, content is to be enjoyed, and to be farmed over time, not in 2 weeks after launch. I don't want other players to destroy the carefully crafted game content because they are in a hurry to farm.
Speed runs should be a banneable offense unless the instance is designed to be completed in that way, or by adding a time attack mode where no rewards can be gained, and only aesthetic items can be rewarded if groups get the gold medal.
So there should be 4 modes for instances:
- Normal.
- Time attack normal.
- Hard.
- Time attack hard.
This is my opinion on this matter.