You have not provided any evidence that can be refuted, only vague assertions.

The compiler is indeed useless for any purpose other than learning how compilers work. It has all the key pieces such as a lexer, abstract syntax tree, parser, code generator, and it is easy to understand.

If the general approach taken by the compiler is wrong then I would agree it is useless even for learning. But you are not making that claim, only claiming to have found some bugs.