Geez that's harsh.
It's interesting that for example a ME Non O marriage visa remains valid even when divorce occurs.
Also for extensions based on marriage the permission of stay does not become invalid upon wife passing.
The odd one out is extension becoming void at the time of divorce.
That is ridiculous.
You require time to sort things out for next step, especially as in OP example of being under 50.
And you call that "abuse of the marriage visa"
Have a rethink.
The "abuse of the marriage visa" is concerning fraudulent marriages.
Nothing to do with genuine marriages failing, which BTW is over 50% in many countries.