really ive never found a problem to this, it takes time to level crafters and it should, if they increase it even more it will just break the market that much more. I always just save them up till i get 70-80 of them and power level my crafters. so you wait 12 days then spend 15 hours total to max out a crafter. its really not that hard to level crafters without leves either. make sure you always craft every single item for that nice exp boost. if you do that you really only need 50-60 leves max to get to 50 reducing your time spent waiting.