It's good in the sense that, as someone who doesn't intend to buy loot boxes, I don't feel like I'm at a disadvantage in earning skins. Allowing people to buy individual skins would make it more attractive for people to spend money because you're getting the "advantage" of being able to pick the skin you unlock. If you get loot boxes through the normal course of the game, you don't get to pick; you get skins at random. As a result, that system would incentivize gamers (who are already buying the game mind you) to spend cash as it provides an advantage in earning skins.
If you can only buy loot boxes, I don't feel any more incentivized to spend money. Purchasing them doesn't give any advantage other than speeding up the time it would take you to earn more loot boxes. It provides the purchasers with the chance of getting the skins they want sooner (and more than likely earning enough credits to buy whatever skin they want), while not providing an unfair advantage that aims to incentivize non-paying users to buy into the microtransaction system.