I mean, operated as an investment property they have near certainty you will have a stable income source (the tenant) so it makes sense that the loan value is higher. You're guaranteed to have the income of the rent checks and just as likely all your other potential income on top of that. You actually can afford higher mortgage payments in that situation -- and substantially so.
Which is a strong, strong, strong argument why all cities which have housing shortages (basically all cities) should be exercising policies that discourage non-owner-occupied properties.