Ah, that's a good point. It's sort of the opposite: now the option holder can wait longer to decide if this is a worthwhile investment, vs "You have 30 days to exercise this or you get nothing".
The ability to extend that period isn't always up to the option-granting company; while it is possible for non-qualified stock options (NSOs), incentive stock options (ISOs) must be exercised within 90 days of termination of employment, by law.