Coding is only one side of being a developer, with design being another important side. Regardless of Rem's coding level, the game's design is unique and they do deserve kudos for that.I commend Rem's dedication, but I assure you that he is not a good (competent) dev. It would be enough to have average programming knowledge to understand that (code of junior dev). Seeing that it's not improving over the years, I assume that he's not really interested in development itself.
And also, I can see that Saria Reclaimed's dev has way better development skills (despite his dubious strategic choices).
Though I understand that our definitions of the term "best developer" might differ.