The problem is not necessarily Mage Wars itself- we have to realize that a 6 year old game has had it's time on the market, and that with it's time passed it won't attract new players like it used to; encouraging more and more content at this point is overstretching the game's life on the market. I'm not saying that the game is dead: the members on these forums prove that there is still a group of people who are playing this game and who want to attract other people to playing the game; anymore content release will please current players, but won't draw enough new players into the game. Changing rules so that they can become more streamlined and easier can certainly help with current players, but it's no use for a board game that doesn't attract more people in the first place.
I've never played Magic The Gathering: I hear it from people comparing it to Mage Wars on these forums, and it's a generally well known game in the board game community. But comparing these two games all the time isn't accomplishing anything, you're comparing a 6 year old game that has run its course to a behemoth that has been solid since 1993- it's a fight that Mage Wars cannot win, and whether or not the game is better then the other is not a sign of how well the game is doing.
Arcane Wonders has struggled to get a game out that rivals the popularity of it's original Mage Wars release, and the overall company's success represents how Mage Wars and other products of theirs have done. Having been on Kickstarter for the last few months, I've seen a Polish board game company with poor English having gone from an unknown company to being one of the best companies on the market today: they have great complicated games that are unique, and they stand out compared to others on the market. Arcane Wonders shouldn't try to sell expansions to Mage Wars on Kickstarter, simply because that wouldn't attract buyers who don't have the base game in the first place: they should instead focus on getting a great product out there that stands out and should be their best product to date; if they know how to properly run a Kickstarter campaign with stretch-goals and the like, then I have no doubt that they can be doing a lot better then they are doing now.
I've said all of this knowing full well that the company is only comprised of 3 members- that does not mean that they can't turn things around and do better.