If there's one reason why basketball doesn't lend itself to fantasy as seamlessly as football or baseball, it's scheduling. With football and baseball, pretty much everyone plays at the same time, so there's never a competitive disadvantage. But with basketball, situations arise all the time where players will only play two or three times in a given week. So even if you have a kick-ass team with LeBron James and Dwight Howard, it's not impossible that you could lose for no other reason than that your opponent's players were on the floor more often.
That, for lack of a better explanation, sucks. After all, it's hardly a competition about who has the better team when one owner's best players have a five-game week, and your best players only play twice. It'd be like entering a poker game with the guy across from you immediately getting an extra $10,000 to bet with. Fortunately, moments where scheduling single-handedly decides the outcome are relatively rare. Even if an owner gets five more games from its players than his/her opponent, they're still going to get annihilated if their opponent is decidedly better. If scheduling was that big a deal, there wouldn't be fantasy basketball.
All the same, coinciding the playoffs of the fantasy basketball season with the end of the NBA's regular reason is absurd, and tertiary factors like scheduling and health can indeed decide who the champion is. Players start dropping like flies. The teams out of postseason contention will either limit the time a player's on the floor or bench them all together; even the slightest injury could spell a shutdown. The same is true for players on teams that are heading to the postseason; coaches don't want to put their superstars in a meaningless game in April when they can rest them for when they really need them. Suddenly, Kris Humphries and Monta Ellis and Deron Williams are out for the year. Tim Duncan and Paul Pierce and Zach Randolph are randomly benched. Players who were useless all year long, like Jordan Crawford and Anthony Randolph, suddenly turn into fantasy monsters, and you wonder why you spent $30 on Jason Kidd when Jordan Farmar is suddenly way more valuable.
It's a maddening, frenetic end to a fantasy season, and it coincides with the weakest, most boring part of the regular season, when many of the good players are benched or resting because they're waiting out the end of the year -- all while your mind wanders between the finale of March Madness and the beginning of the fantasy baseball season. It's impossible to look at what happens in the final two weeks of the season and determine that it's an actual representation of what the rest of the year was like. Besides, even ardent basketball fans don't like watching NBA games in April, which have all the enjoyment of watching an October preseason game between players who you know will never get off the bench.
Which is why in the future, if you're in a system that allows it, you should consider joining or creating a league that ends a week or two before the actual season does. It'll save you from cutting ties with many of your players, and will allow the championship to be decided when a higher degree of basketball is being played. True, it'll give you less incentive to pay attention all the way through the season, but not watching those games in April is something you'd have to live with.