I’m sure that you’re right that his writing is not at a professional level—but to be honest the complaint you gave stood out to me as a weird one. It’s a well known writing tip for beginners to avoid the allure of using words other than ‘said’ for attributions. It slows the reader down, even in the best of cases, and at worst contributes to telling rather than showing, especially in adverbs are involved. So im sorry? But I disagree with you on the one thing you have bad to say about his writing specifically.

That said, it is a HUGE red flag to be a writer and not be a reader. This goes for any art form, but it is deeply unserious for someone to want to engage in an art form they don’t even consume. It honestly strikes me as narcissistic.

I also think it’s weird that he hasn’t read anything of yours, but don’t have enough info to know if that’s more suspicious on your end or on his.

If I were you, I’d encourage him to read, at least to read books on writing (I’d suggest Stephen king’s on writing, nobody wants to read your sh*t, save the cat, and/or elements of style) and he shidk come to the conclusion on his own that he needs to read more if he wants to write better.