Its just that were playing a lot of mediocre cards, and it doesnt seem like it would cost us that much to splash red (for Unlicensed Disintegration, if nothing else)
Ive excluded [casthaven]Gemstone Caverns[/casthaven] (which essentially lets you turn being on the draw to being on the play), [casthaven]Urborg, Tomb of Yawgmoth[/casthaven], and [casthaven]Vesuva[/casthaven] since they dont produce multiple mana (but can when combined with lands on this list)
(Creatures in a log together can't be blocked unless they're all blocked
Youll generally want your mana curve to be a bell curve of sorts, with a few one- and two-mana spells, a higher concentration of three- to four-drops, and then a few cards that cost five or more
The comprehensive MTG rules say that "you may cast" a card exiled by Cascade, so it counts as casting that spell