The difference between a mini-expansion and a kickstarter for an expansion is that in a mini-expansion, the company takes the risk. They fund the development then sell it. A KS for mini-expansions shift the burden of risk to the players.
The free-er I make the game, the more you will have to deal with in-store F2P style mechanics to make up the money. I am more loath to go that route than I am a expansion approach. So, to me it is the lesser of two evils.
Gamers have been comfortable with expansions for decades, well before F2P. I guess its a model I'm comfortable with too.