The simple truth is although there has been a major resurgence in hardware buying and expansions, it's obvious the lack of coders means there is not as much interest that side.
As has been said earlier in this discussion. Planning and programming an Amiga game takes a lot more effort than an 8 bit game.
Also the c64 has kept its scene coders about. Sure we have a handful of Amiga scene guys here but due to the constant changing of the Amiga many either moved on to PC or into mobile.
The 8 bit machines have not changed much making it easier to code for. The Amiga has various processor upgrades making it much more difficult to keep all users happy.
If you have to compare it to any machine it is like the PC. Various configurations, various different ways to go. It equally is now suffering with a lack of home brew games.