The reason the '94 AWB had "loopholes" was because their goal was to get something passed so they could establish precedence. They knew there was no chance if they proposed what they really wanted right out the gate.
The '94 AWB was there way of testing the waters to see what they could get away with and to see how we would react. They knew there were "loopholes" and intentionally put them there so when people pointed out how useless the ban was, they could say it would work better if it was stronger. They didn't go after private sales for 2 reasons. 1) They knew it would be a hard sale and 2) They knew we would take advantage of it and they could use it against us in the future. In a way, they gave us enough rope to hang ourselves. So now future bans will "attempt to save us from ourselves" by stopping said private sales.
Contrary to what we may like to think, politicians aren't stupid. They just know it is easier to get what they want a little at a time versus all at ounce. They know that if they ask or demand, you'll say no. However, if they make you think it's your idea, you'll willingly give them what they want.
A perfect example would be how machine guns were banned. I'm sure prior to prohibition, machine guns weren't a major concern. Look at the 1927 Thompson, it was marketed towards ranchers. Fast forward a few years to 1934 and all of a sudden public opinion had swayed enough that the public gladly went along with a maching gun ban. Why? Because only criminals use machine guns and making them illegal would take them out of criminals hands. Sound familiar? That was almost 80 years ago and they're still singing the same song.
The government knows it can't ban all types of firearms at once, so they don't. They know they can take advantage of situations to ban certain types of firearms, which will eventually lead to total confiscation, so they do. First was machine guns, then assault riffles because they're machine guns, now they're starting on semiautomatics. What's next?
Imagine if the government would have proposed to ban all weapons in1927. It's taken them almost 80 years, don't think they will stop anytime soon.
Sorry, for the rant.