Freeroll is aim to attract new users. If it sets some thresholds, why people play there?
The problem is that micro freerolls don't attract the kind of people that a poker site needs to survive. If a site has, say, a 1BTC/wk promotional budget and puts that budget into running 6 chips worth of freerolls a day, the only people that that is going to attract are people like you who just said that you aren't interested in depositing on a site. Now that's obviously fine for you as an individual, but for the poker site that's bad because they are never making any money.
If, instead, the site puts that budget into deposit bonus', guaranteed tournaments, or funding a rake race promotion of some sort, they are more likely to attract players who will actually deposit money and play regularly, allowing the site to rake pots and start recouping start up costs. These types of people are also more likely to leave bonus money on their accounts and play more.
I think poker site owners are rich enough to give freerolls. They have earned enough from poker, and have enough fund to run the site.
Investing and running a poker site is not an easy thing, biggest poker sites like pokerstars, full tilt, 888 and so forth. Every year they pay over 10 millions of USD to sponsor competitions, players. Only experienced and rich owners can run poker sites well.
IMO, in the crypto community, the best way to run a poker site is freeroll. And it needs lots of time to be a big poker house, maybe half a year or longer.
I like freerolls, currently I am joining freerolls in luckyflop, I can earn many mbtc per day. Sometimes I go to SWC, betcoin to play freerolls.