So why has the somewhat bearish market of the last couple of months seen not only the highest difficulties on record, but also the largest difficulty jumps?
Difficulty keeps growing because we are in the middle of a technology change (GPU&FPGA -> ASIC) and mining with the new technology is still lucrative
is the whole ASIC mining scene going to come tumbling down as people realize they have been scammed with effectively useless devices for which they will never recover their initial investment?
I don't know if it will be "tumbling down", but you can bet that many miners will have to shut their rigs off, and will never recover their initial investment in BTC.
This already happened in both 2011 and 2012, so nothing new under the sun.. The mining market adjusts itself so mining is only marginally profitable, except during notable exceptions as we just had from February to now for the few owners of ASIC miners.
Nevertheless, the limited window in which ASIC mining was wildly profitable is closing right now.