stretching ears :3

i have waited so long to stretch my ears again. why do kits make the sizes jump from 3.0 to 4.0?!?!? we all know that's a unhealthy sizer jump >:( so i looked everywhere for a kit that jumps by .5 and i finally found one. they are teal and really cute :3 but i still dont understand why brands wont just make the sizes what they're supposed to be? wouldn't they sell more product if they js did it right?