Fuel will also be the reason in the L2, we don't want to go back to the ramp for fuel if we can help it or divert when inbound and being held for ILS traffic, particularly if the met office issues coastal tafs and the airport then closes for snow that isn't forecast until hours later. Every minute can count for us.
In the 225's with greater fuel capacity and higher AUW it may be more down to pilots not seeing why the runway isn't being sectorised to allow more efficient use of the space, and inbound, not wanting to completely drain rigs of their fuel stocks, may be similarly tighter on fuel thus limiting available holding times before a diversion will be necessary.