Some will retrench and dig in their heels.

You have succeeded in insulting a lot of very intelligent, well heeled and sophisticated folks in so doing. 

The banks realized they were losing out back in the 80's when rates spiked so they stopped writing assignment clauses in mortgages.

I found one that broke it down by decade but didnt go any deeper to see any dips or spikes.

You'll need to pay them double to spike their interest, usually they get paid 10/hr. 28 units can't afford full time maintenance.

Dirt/mud and heels don't work well.

our market is pretty steady, we never see spikes, even through the crash, we maybe lost 20% from the top of the market. that being said, its not common to sell a house quick either, so a 150 DOM is pretty standard, even if you are priced right. 

But could bad tenants also contribute to the rent spikes?

The biggest issue I think you will have is when the electric bill spikes to $500 one month.

I am certain every market is different but around here when we are in a down economy investor activity actually spikes because properties are cheaper.