When you say there is nothing wrong with having unimproved dirt roads to travel, it depends on who you ask and what you ask of them. If the BLM is responsible, or any other organization or entity, for maintenance then there is something wrong with unimproved dirt roads. They are very expensive to maintain, to monitor for vehicle travel/traffic and for recovery costs and damage claims. I managed an area with dirt roads and it was very costly and we regularly had complaint and claims for vehicle damage.
The governing body for the area I managed looked at the cost of maintenance over time versus adding a chip seal to the dirt surface and realized very quickly that dirt roads are like the Jeeps that travel them, a hole that you can never fill, regardless of the money you pour into them. Add a chip seal and you can extend the life, lower the cost and provide a level of service an unimproved dirt road cannot. So, there can be something wrong with them, based on the expectation of the driver and expectation of the tax payer.
Not saying a chip seal was the right decision, just that there are valid reasons, agreed with or not, for adding chips. Oh, and chip seal is usually applied to an already asphalted road, to extend the life and add safety. It's usually not added to a dirt surface, although it was in the area I managed. We specifically added it to a dirt surface and in my mind that's not paving the surface; although, I can understand the argument that others would make that it is. In my mind it is more of a binder and adding additional rock, but that's my "opinion."