In my opinion, I can be a worst UX expert in the world, and I still reserve the right to criticize bad UX elsewhere: the fact that you are a bad "creator" does not mean that you are a stupid "user".
Yes, it is a bit hypocritical, but you can look at the content of the message and judge it without judging the presentation of the message, even if it talks about usability of interfaces in computer software.
Sure. But as Ray Dalio suggests in Principles (https://www.principles.com/principles/633d5d13-8610-425f-ad6...), you will be more likely to succeed at your task if you believability-weight the information you receive. When considering a military strategy, you should probably weigh the advice from a 4-star general who's served in similar circumstances over the advice of a 4-year-old boy who is relying on his experience watching Paw Patrol.
As the worst UX expert in the world, you can obviously feel free to criticize others, but you're probably going to lose a lot of people after the first sentence if you're using 2003 MySpace-style blinking text and animated GIFs to make your point.
But, if a 4-year old boy finds "there's more of them with bigger guns", and a general has a personal interest in hurting someone without you knowing that, you'd be unwise to not consider the words of the boy as you prep your military strategy.
Note that you were careful to establish hard-to-prove circumstances ("served in similar circumstances"), which seems to say that you don't want to discount what the non-expert is saying too easily either.
Yes, it is a bit hypocritical, but you can look at the content of the message and judge it without judging the presentation of the message, even if it talks about usability of interfaces in computer software.