1. The decision to clear out one's entire Minecraft
folder and start from scratch, commonly done when there are irreversible conflicts between various mods installed over time.
2. The decision to delete one's worlds in Minecraft and start over with a blank slate.
My Minecraft installation has too many mods and I've run out of block IDs! I tried running an ID resolver mod but that just made it worse. I ended up declaring Minecraft bankruptcy.