The  Non-FiT producers systematically going bankrupt due to pressure from forced purchases of from FiT-Producers will kill the grid.

If the lights start flickering,  laying the blame on renewable energy policy will succeed (because it will be correct. Not due to underlying tech, but due to poor policy design) and the babies will all go out with the bathwater. Not a desirable outcome.

The feedin tarrif is just utterly incompatible with a market in power production. A tax on carbon? Sure, that is the kind of adjustment signal markets do well. But the current monstrosity of a cross between dictating what to build and letting markets handle it is not clever.