Not switching to metric for time is reasonable, because there are already two existing 'natural' units for time (the day and the year), and they don't align on each other in metric (a year of exactly 1000 days would be so much easier, but we'll have to deal with reality as it is... or accelerate the rotation speed of the planet I suppose).
So long as we live on earth, metric time won't make much sense.
Not switching to metric for time is reasonable, because there are already two existing 'natural' units for time (the day and the year), and they don't align on each other in metric (a year of exactly 1000 days would be so much easier, but we'll have to deal with reality as it is... or accelerate the rotation speed of the planet I suppose).
So long as we live on earth, metric time won't make much sense.