Investing into The Spoils would've required the potential playerbase--Magic players--to have put aside a LOT of what they knew about game play and about the "color pie" as it is to try something new. Admittedly, it's a lot easier to get into if you know something about other card games; I found a lot of similarities in The Spoils to Versus, especially, having played both games. However, many people don't like making that kind of jump, especially when money might be tight already. Others probably didn't get or enjoy the humor of the cards. I remember explaining the game to someone once at the shop and getting a blank stare and a statement about not wanting to play an inferior version of Magic.
I guess that's the way things go, sometimes. I like the game overall. I don't know that I'd call it superior to Magic yet. In The Spoils, archetypes are much more defined to each faction than in Magic, a consequence of there not being as many sets to pull from yet. For example, the Bankers ARE blue/white control. Period. Rogues ARE random kooky effects with some flying. Warlords ARE combat and burn. Gearsmiths ARE combo. Arcanists ARE classic, do everything, old-school blue. There's just not a lot of bleeding between colors yet, which can make for a more limiting experience unless you're looking to run a two-faction deck.
Overall? A good game, with lots of potential, but it's not had the time to reach that potential yet. Another year, a few more sets, sure!