I care. One of the 10 purposes mentioned in Srimad Bhagavatam 2.10.2 is 'sthanam' - or explanation of planetary systems. I think it is important for us to have a definite understanding of the cosmos we are situated in as it has an effect on our world view and behavior. Sukadeva Goswami also thought it was important to include descriptions of the hellish planets in the Literary Incarnation of Godhead.
If we assume that it doesn't really matter if the Bhagavatam is true or not then we run the risk of further assuming that everything therein is relative and can be accepted as literal or rejected according to our whim.
I won't guess at Srila Bhaktivinode Thakura's motivation in writing Krishna Samhita with less emphasis on the literal descriptions of the hellish planets and other aspects of our teachings. I don't think that the Thakura expected his own followers to adapt a compromised faith in Bhagavatam as a result of this one book though.