The currency you currently buy exotics with is earned through luck outside of strikes. The suggested system allows you to buy luck for time.

Sorry still don't like it. Levelling up is determined by your armour (light). Buying items with glimmer makes it easier. I can make 10000 glimmer in 90 minutes of play. At that rate by the end of the week I could have 100 strange coins or 100 motes of light. It would become farcical if we had players running around with that sort of currency.

15 hours worth of farming for a single exotic sounds fine to me. Let me point out that with the current (and I am not saying remove it) system you can earn a full set of exotic gear faster than 15 hours if you are lucky enough. The likelyhood of being that lucky is very very very very very low but it is possible because each reroll of luck won't remember the last. Think of it like a perfect 10000 side dice, each time you roll you are mathematically getting less likely to roll a desirable number but the dice in actuality doesn't remember the last roll. So it is equally likely compared to the previous roll that you will get another desirable roll.