Unethical maybe was too strong a word, but basically I don't think the BCCI's approach is in the best interests of fair competition.
Imagine this. What's the richest football league? The Premiership, quite comfortably. There are clubs in Spain, Italy etc as rich as those in England, but the uniform TV deal in England makes the FA the closest thing to the BCCI in football. Imagine, then, that the FA decided certain players who had played in a certain competition where therefore not eligible to play in the Champions League of football, and that they had the power to enforce that decision. Football fans wouldn't have it, there would be bloody outrage, the competition would be regarded as a laughing stock and not really bothered with.
Cricket could win out here through this Champions League, I think it's a great opportunity for domestic cricketers to shine, and I think it's a great chance for us to see which domestic leagues are strongest. What's the point in the BCCI manufacturing an IPL champion? Let the best team win, what has happened elsewhere is a total irrelevance.