If they had kept both exchanges as they were you would have the following broken rep grind. Not saying it's efficient, but it would definitely be broken.
50 materials --> 5 marks, 25 rep
10 marks --> 20 materials
100 materials --> 10 marks, 50 rep
10 marks --> 20 materials
80 materials --> 10 marks, 50 rep
10 marks --> 20 materials
80 materials --> 10 marks, 50 rep
And so on. Keeping it, the system would've created a broken rep grind.
English
-
So remove the rep and keep the marks. Problem solved.
-
It would also allow currency convesion and defeat the weekly mark caps. See the original link for more discussion.
-
No it wouldn't: material exchange has always counted towards the weekly caps. So the conversion would have gone more like this: 1000 materials --> 100 marks, 500 rep 100 marks --> 200 materials, 0 rep 200 materials --> 0 marks, 100 rep 0 marks --> 0 materials, 0 rep IOW you can get a 20% rep bonus at the cost of throwing all your marks away.
-
Spending marks doesn't reduce the aquired weekly total, so swapping one for the other wouldn't impact the weekly cap. If they decided people would gain to much glimmer, they could have reduced or cut out the glimmer gain entirely. Now, people will have nothing to do with all their excess materials. Other than upgrades, there is nothing to spend them on and even more ways to aquire them. The exchange worked because materials weren't hard to aquire in the 1st place.