The lifegain makes it very useful when paired with the likes of Gourmand's Talent or Trudge Garden to create a bigger army and, of course, more fodder tokens to sacrifice
Well, Dromokas Command can fight the creature you need to kill or protect your battlefield from a sweeper like Anger of the Gods
Blistering Firecat I might be giving Blistering Firecat more credit than it deserves, but its hard for me to see 7 potential damage for 4 mana and not want to take the risk of including this red card in my deck
I probably play more enters-the-battlefield tapped lands than most folks, since my local environment with the other RC members is pretty slow, so I see how Tiller Engine might be something that I get a little extra mileage from
Clones are great in Magic
Still, as long as I had a bunch of them in my deck, the upside of a free spell is worth the inherent risk of putting a colorless land in my deck