I agree. I've seen beautifully made scripts that break down each comic page panel by panel with considerable effort put into describing the intent, sketches to suggest how the composition should be handled, and well written dialogue- all polished to a shine. When a writer goes this far, you can see they know what they're doing.
But here's the thing- I rarely if ever have seen a comic writer able to do this who isn't also an artist to some extent, or has at the very least put considerable effort into trying to draw their own work in comic form (and often realized that it is an immensely difficult skill set in its own right, and they would rather focus on writing)
On the reverse, I often see writers who don't have any grasp of drawing at all making the same mistakes. Comic scripts written like film scripts. Action cues that don't make sense because they don't seem to realize each panel is a tableau still where only one thing can happen at a time. Descriptions that place a lot of emphasis on one very specific detail, but leave out tons of important information an artist would require, such that you have to go back with a whole list of questions to make sure you're not departing too far from the original concept- because in a novel, you can get away with describing only what's necessary- not so in a comic panel where characters are interacting with objects in a fully realized environment. The list goes on.
This goes back to the director-set designer comparison I made in a previous post. I loved working with directors who had tried set building at least once in their lives and had some notion of what was required, or at least of practical constraints. But every now and then you would meet a director who was an "ideas person". They might work well with method actors, but the rest of us were tearing our hair out, running around, doing twice the work just to get their crazy unfeasible ideas in line and turn them into something that functioned in real life.
Now the thing about that is- if you're trying to build a theatre set and you don't know your stuff, you're not going to get very far. Similarly, if you're an illustrator who can't draw hands, or struggles with perspective, those are very concrete skills that you simply can't do without. But I've seen directors and comic writers who somehow manage to fly by the seat of their pants for years, relying on the skill of others to carry them through. When you do meet a skilled writer or director who really knows what they're doing, they're an absolute gem- and I have a few I think of very fondly. But there are so many more problem writers and directors that I've worked with (who nonetheless think they're brilliant, and are still very much working in the same way, despite multiple artists and set designers having struggled to basically elevate their work to an acceptable standard)
So while I deeply respect skilled comic writers, I tend to be more cautious around people who simply describe themselves as skilled writers- because I've seen so many instances of writers whose work was made "good" by an artist who put in double the effort, and likely wouldn't have stood on its own merits otherwise.
Basically, my attitude towards such individuals is "As an artist, I have to show you my portfolio- so let's see some examples of your scripts first."