To me, "house farming" is buying a ton of houses and placing them in rows with no spaces between them. That's basically how a real farm works. But having lots of houses that are nicely arranged on streets with lawns and decorations is not house farming. That's just creating a realistic-looking town with places for everyone to actually live.
While I don't like house farms (even though I had a modest one for the first few months I was playing until I got to max level), I don't like it either when I see people have only bought the minimum houses required by the game (one of each type). What kind of town has around a total of about twelve houses in it? Certainly not Springfield.
Anyway, I can't accumulate cash too quickly since I don't have a huge house farm nor do I have tons of premium characters and multipliers. I've been playing since October 2013 and have everything you can buy with in-game cash (except the $1 million+ aspirationals), all the land, and the entire ocean front. I've bought as many Squidport tiles as I care to buy, and I'm at about $8 million on my way to the Sit 'n Rotate.