Ok. Here is the deal. Anti-gunners practice incrementalism to get there agenda passed 'little-by-little' because they know they can't get to their ultimate goal in large chunks .
Consider this famous scientific experiment. Bring a pot of water to a boil then throw a frog in. It will immediately jump out. However, put the frog in the pot and turn the temp up little-by-little and it will stay there and get cooked.
The antis have found this also holds true for infringements on personal rights. When they come out with attempts at wide spread bans they are resisted strongly by the majority. However, when they seek small pieces of legislation they claim to be "reasonable", many more people are willing to allow them this small victory. However, they always find excuses to come back for more and more.
When it came to attacking military style weapons to make 'soccer moms' feel more secure the antis needed a way to identify and vilify the weapons they wanted ban. What they did was thumb through gun magazines choosing weapons that had a military appearance and then presented these semi-auto rifles along side of the full autos they look like in order to confuse the public between the two, often talking about them interchangeably. To further make semi-auto military LOOKING rifles appear less like semi-auto hunting rifles and more like machine guns, they focused on the magazine capacity. Most semi-auto hunting rifle used low capacity magazines for practice reasons (lighter weight, more maneuverable, etc) while machine guns use large capacity "clips."
The antis expect the public to be too ignorant to understand that it only takes a matter of seconds to swap a magazine. When it comes down to using two 15 round magazines compared to three 10 round magazines, the latter only requires one additional magazine swap that only takes a matter of seconds. And what about a 10 round .45 cal magazine compared to say a 12 round magazine?
Again, magazine capacity is nothing more then a gun grabber ploy to vilify a type of weapon and make it appear less like other weapons so they can get away with another small victory on the way to their ultimate goal.