Some areas of the industry are "discretionary/luxury" like scenic flights and tourist transfers. These areas suffer fast when people tighten the belt.
I've done a fair bit of real estate photography in the past. Next time I do that it will likely be from the ground, with a controller in my hand, unfortunately.
The above two downturns mean low hour jobs are even harder to find.
This reduces the numbers training, so less instructors are required.
As far as mining goes, "stream sampling" used to employ quite a few pilots. I'm pretty sure not much of this goes on any more.
There has also been a move from many smaller machines to fewer larger machines in fire/flood operations. Fewer pilots required, and many fewer less experienced pilots jobs.
Even though the Off-Shore industry seems to be in a race to the bottom as far as conditions go, the fact is there are more jobs than ever in that industry. No one is going to the rigs by boat. Pilots are just changing suits, and working for a different circus.