Theory behind big Add-On's?

[Small Fry]

Lets say the structure is $20 buy in - T2000 / $20 rebuy - T2000 / $20 add on - T3000

I need some help understnding exactly the purpose of setting up your tournament with this structure. Specifically the add on. Unless it's purely for increasing the pot then I guess I understand.

I assume almost everyone does the add on so why not just charge them more up front and increase the chip counts. Say $30 buy in - T2500 / $30 rebuy - T2500. Do the players just feel better paying $20 three times rather than $30 twice?

I also understand everyone likes a bigger prize pool but it's the players themselves that fund it. If I put out $50 for a chance to win $500 it's the same as putting out $100 to win $1000. Theoretically it's the better players that benefit. Do we all believe we're that "better player" so the whole rebuy / add on system benefits us by all the fish dumping in dead money?

Am I being to cycnical? It just seems with this structure I'm telling my players "It'll only cost you $20 to buy in initially but I've created a blind structure that will pretty much require you to cough up another $20 later if you want to compete. But before you get to that stage you also have to deal with the possibility of losing the chips I'm giving you now (which in effect is an insufficient amount unless you get real lucky) in which case you'll need to buy more (of the same insufficient level)"

Somebody set me straight. Tell me I'm an idiot (about the add on, not just in general) and just don't get it.