Can anyone tell why magento saves product attribute multiselect as varchar and hence its options in catalog_product_entity_varchar as array?

Is not it better to consider multiselect as "multidropdown" and save it like an int and insert multiple records in catalog_product_entity_int?

If it were so i could join catalog_product_entity_int with eav_attribute_option_value on value=option_id

what i can't do with catalog_product_entity_varchar if value is an array.