This wasn't a marginal increase. It was a very dramatic tightening. Marginal would be going from 2.5% to 2.75% or 3% .. this was doubling.
And they did not telegraph anything. If you tracked the CME fed funds probability you'd see that it waffled up until a couple of months beforehand and we were at 0.25 for a very long time.
The reason 0.25 used to work as a min step was because a) we were never at such low rates for so long before and b) things didn't have a chance to settle into a particular rate structure so it wasn't really an issue. The difference this time was everyone started building businesses based on 0.25 and had time to do so.
Agreed, you shouldn't be doing that. But heck, the economy is pretty messed up so the rules have changed.