To be honest, we expect a lot from rail companies to get us to destinations no matter what the problem.
I have written elsewhere about National Express dumping me 10 miles short of my intended destination this coming Wednesday because of roadworks without any suggestion about onward transport or using a different vehicle. The railway can't (currently) get away with that.
As written elsewhere, truly disability compliant coaches have not caught on as having a high floor is one of the features which distinguishes a coach from a bus. Hiring service buses rather than coaches at short notice is obviously difficult.
Maybe the outcome of all this will be the far easier to implement notice not to travel advice rather than have train companies do their best to get people past an obstruction.
Being able to divert trains doesn't just need route knowledge - it needs suitable traction, crew hours and paths. 'DIY' diversions may be appropriate in some cases.
