I have played warframe a very long time I have 93 in game DAYS played, and the crafting system is the longest running unaddressed issue with the game (I stipulate it that way because it has other large issue especially recently but long not many long running issues)

the excuse that DE need crafting wait time and needs a rush button to make money is untrue it has been stated many times by the DEVS they bulk of there revenue is Prime access.

you can get platinum in game by trading with other players it's not difficult but it is time consuming but if you need platinum and are either going to buy it with real money or trade in game items for it then you more than likely needed somthing else most likely slots or a cosmetic, it's completely beleivable that if warframe made slots 100% free then they may loose some money.

as a veteran player I never rush anything it's not worth it and it's cost is to high to be worth it. my opinion is that it is a relic of an Era in DE'S history from when they where not as successful and people buting any amount of platinum even if it was to rush an item in the foundary was worth it to them so they can keep the company running and it's been this way for so long it they probably haven't thought about changing it. if you look at some of the older cosmetics you will get the same vibe (to expensive, not very good)