With respect I think you haven't spent much time listening to pro-gun people.
Different people have different opinions. Sure, there are some absolutists. But that's not everybody.
The 'line in the sand' that almost ALL pro-gun people will get behind, is semi-automatic small arms- pistols and rifles and shotguns and the like, as we know them today. Not machineguns or rocket launchers or cannons. Do you see people rallying on the steps of capitol buildings demanding machineguns and rocket launchers be re-legalized? I don't.
If you want to understand why there's no negotiation, this comic explains the pro-gun position pretty well.
To put that in perspective, you must understand that in the early 1900s, you could order a machinegun, a fully-automatic weapon (hold down the trigger and it will rapidly and repeatedly fire), through the mail, delivered to your doorstep with no background checks or other interference. And you'd order this from a hardware catalog. There were shooting competitions in school- kids brought guns to school all the way up to the 1970s or so because shooting was a competitive school sport.
So follow the history, and it's the same thing repeated over and over. Anti-gun people want to compromise, we'll regulate this but not that. Wait a few years and it happens again. Go through a few iterations of that and guns are now one of the most highly regulated items you can (sometimes) buy. And yet there were no school shootings in 1920, even though you could buy a VERY effective firearm for such purpose in the mail.
So I suggest instead of writing off anyone who takes a pro-gun position as a 'gun nut', you should try listening to those who disagree with you and try to figure out WHY they disagree.