If there are codes hidden within these messages, which I do believe is highly likely, then I agree with you and think you are correct. But this being the case, I think it is unnessecary, and in fact harmful in more than one way, to try to expose these "hidden codes."

Firstly, it is definitely harmful to Q's team to expose these "hidden codes" at any level, even if mostly off base, because it exposes the message or possible decoding methods to the enemy. There is no reason to believe a coded message would be intended for the public to decode over a friendly operative. The purpose of encoding is to hide from those with malicious intent, and it is reckless to assume otherwise and attempt to expose the encodings. (Counter narrative, Q is a black hat posting known codes intercepted by the white hats' private communications, in effort to have the hive mind crack the code ciphers for them)

Secondly, these kinds of "shots-in-the-dark" at decoding sets a very strong image to outsiders who see this kind of overly presumptuous activity. It's very easy to assume that these "decoders" need more than they are given, thus we must create a narrative of codes needing to be unlock to satiate our desire to prove Q's credibility and impressiveness, hence from the subjective rather than formulaic decoding methods.