Wonder if you ever looked on the Pinegrow website or read the documentation. Pinegrow Pro has nothing to do with WordPress and comes with regular HTML and some frameworks like Bootstrap and Foundation. Only when you want to use WordPress you can get that at a extra fee and for Tailwind the same procedure.
So I don’t see the problem you describe! And instead being so negative maybe come with a suggestion from your side to make Pinegrow better!
Regards,
David