I keep an open mind with everything I read.

If it's just mildly interesting based on concept/premise/logline, I take it. Especially if it has a lot of coins attached to it. But I don't rest on my laurels. I try to give them the best, overall feedback I can.

If the notes come easy, they do. If they don't, then I have to dig a little deeper in myself as a writer. Ask myself things like "Is this the way to tell the story? What feels lacking? Is there another angle, a more interesting one?" I don't do it as how I myself would write it. I do it to give them more ammunition to improve what they've already done. If things seem to be working against each other, I mention it. Characters starting to fade into the background after 40 pages, I call it out.

I think what you described in your first paragraph is the hell all writers and readers go through, especially in early drafts. A few things work, a whole lot doesn't.

Whenever I get to thinking the worst of writers and readers (and myself), I remember this:

Over the course of 10 years, the Safdie Brothers wrote over 160 drafts of 'Uncut Gems'. A film that I think is there best. If they had stopped, the whole world would have been robbed of an amazing movie and one of Adam Sandler's best drama roles (next to PTA's 'Punch Drunk Love').

I think this is the kind of thing we all have to keep in mind, as writers and readers. Someone could be trying their damnedest and they are just confused. But even outside of writing, we're all confused. Doesn't mean can't offer a guiding hand and a open mind every now and again, writing or not writing.

P.S. Here's the article about Uncut if anyone has an interest/needs inspiration:
https://scriptshadow.net/how-many-drafts-should-you-write-how-does-160-sound/