They have literally not been doing that for over 2 years. That you are still whining about it as though this is sudden reflects more poorly on your character than theirs.
when you compare the gems/hour rate is was hugely decreased through out the years
today only rich boys who can buy real life free time with money can afford spending weeks and months farming to obtain an amount close to previous years
What I can't come to understand is why would konami risk to get f2p even more angry just to nerf 5 gems? If you are gonna do that make it worth and remove 200 gems or something. I mean even if they stopped giving gems their maso chistic f2p playerbase would still open the app everyday