You are talking directly about a single botbase. I'm talking as a whole.
the one botbase is the whole. it doesn't mind if i talk about 1 botbase, or 10 profiles. it is the point for everything that you find.
everything that is offered for free is overused until it isn't useable anymore.
the store keeps some things exclusive. and thats good.
take the excellent work of Echotiger as an example. his profiles are good, and free.
now move your char to gundrak, halls of lightning, tolvir,... whereever. you will see 20 bots per minute (probably more) walking in and out the instances. it are echotigers free and good profiles. why do i know that? cos nobody would place a mobile guildchest at the dungeon portal except echotigers profiles.
before echo published his profile pack i was almost alone in all wotlk dungeons. for more than a year. making it public destroyed this way of botting. now you get banned within days, and loot is nerfed too.
there you see it. everything that is free is overused. this forum has meanwhile more than 200.000 registered users ( 228,726 to be exact). sure, some bot with other bossland products, some don't bot at all. but others bot with 20-100 bots.
paid profiles gives you something that not everybody does. and it is fine to have to pay for something that not everybody has.
edit:
What will happen if everybody uses the AHBot from the store? It is a good bot. and it is paid. if to many people use it, it is worthless.
What will happen if everybody uses profile xyz from the store? it would be useless, see example of Echotigers profiles.
What will happen if everybody use whatever from the store? can you figure out the answer for yourself?