im okk with that ratio, a bit fast in my opinion (elite dangerous isnt the classic game you play for 1000 hours), you can surely reach more than 5000h if you like the game like me and many many other cmdrs out there. i personally play from day one with some stop and go douring the journey.that would be better than what it is now. personally I think about 8000 merits/hr average would be about right. that would 100 hours to max out.
Anyway, 8000 merit\hour CAN be a good ammount but you have to grind as hell all the 60 minutes of game to reach it and not just delivering rares in loop sitted in private group, thats not a cg with a personal reward but is powerplay, a community gameplay things, its the endgame content for player who have do all the kind of stuff i dont see nothing bad if a new player need more than 100 hours to unlock some powerplay based weapon. you can deal the game without having it! it is like the final raid equip like in any other mmo, you have to play waaaaaay moooore than 100 hours in regular online game to reach the endgame gear. (and no one have problems about that in other games)