As the subject says. It's been entered into their custom "bitch at the user with a popup until they disable it" database. To be fair to the developer, he has solid reasons for his stance. I'll try to summarize as there is a lot of misinformation and emotion out there fogging the issue.
1) The Palemoon project does not have enough developer juice to debug other software and addons.
2) Various users: "[website] does not work with Palemoon. Fix your shit, Moonman!"
3) Moonman: "Known issue. Stop being morons and disable NoScript. Thank you, and have a nice day."
4) Various users: "We did. Same problem. Fix your shit."
5) Moonman: "Oh. That's an actual issue with Palemoon then. I'm on it!"
6) Much hacking and cracking and time and talent are expended to no effect. Surprise! NoScript does not follow the standard of letting go of the browser when disabled. It lingers on. It has to be completely uninstalled with an added cache clearing operation on top of that.
7) Moonman: "It's NoScript. Get rid of it. Have a nice day."
8) Various users: "No. FIX YOUR SHIT!"
9) Moonman: "Crush. Kill. DESTROY!"
If you roll with my simplification you can see his point.
I have two observations. First, quite a few sites have a technical support checklist that runs like this: "What browser are you using? Palemoon? Oh good! We have two fixes you may choose from. One, use another browser. Two, go away and do not come back."