So given full auto are rare...and hard to get a license-wise and...

So given full auto are rare...and hard to get a license-wise and expensive... we're really talking about semi-auto ar15 platforms

A semi-auto.

So tell me why isnt the handgun...say any 9mm 45 or even a 38 Special et al...the target of gun haters?

Anyone proficient with a h/g could kill just as many kids as with an AR.

The answer to clue you in is they WILL come after the h/g...but they know that's the biggest push so they'll go for the low-hanging fruit and then when they feel theyre ready...they WILL come for the h/g

Not the h/g of the crimes, of course.
Nah.... they'll come for the law-abiding owners that have never and never would use the weapon for anything illegal

And the folks know this in their bones and they don't trust you, the Gvt or any bleeding heart that assures them that's just redneck paranoia.