Yes and yes
The rules are really set to give clarity for people who are"tax resident" out of the US (or the UK or Australia) but who still like to visit home as much as they can - so there's a limit. And it has to be simple and clear to avoid endless argument about the definition of a "day"
The people this affects are normally well aware of the restrictions and carefully document their travels for this very reason - plus you avoid being dependent on a specific flight at 23:00 on day 90 in case of weather or cancellation issues.