"allegedly," but really any player who is well known and plays at a high level is going to have haters. I would expect lebron to have haters, donatas motiejunas? Not so much
I think you're right that part of the hate surrounding Lin is due to issues about class in this country. For example, I recently read a Knicks board post in which one person said it is easy to relate to Lin's story because he seems like a regular guy, and another poster disagreed by pointing out that Lin's family is rich (not true, actually) and that he went to Harvard and his schoolmates are from the elite class -- so it is actually hard to relate to his story. In other words, Lin is associated with privilege -- in contrast to the rags-to-riches stories of many NBA athletes. My own theory about the hate surrounding Lin is that it is related to the deep ambivalence about affirmative action in this country. While everyone recognizes the long history of slavery and institutional prejudice in America, many Americans nevertheless feel uncomfortable and even resentful about addressing this by giving minorities special treatment in college admissions. This relates to Lin because I've often heard it said that he only gets this much attention bc he is Asian. There is, to be sure, truth to that, but what is noteworthy about such comments is they express a resentment about Lin getting fans and media attention and (future) All-Star votes because of his race -- just like how affirmative action gives some minorities special treatment. Many Americans would prefer to be color-blind and act like racial differences don't exist in society at all. That race is part of the appeal of Lin's story goes against their idea of equality -- no one is supposed to care what someone's race is. As with many views surrounding race, it has its own contradictions. Lin is viewed as getting unfair special treatment, but being Asian also has, on some level, made his basketball career more difficult. Affirmative action and Asians also make for a complicated issue. University admission quotas based on race limit the number of students with Asian background regardless of their qualifications; if race quotas were lifted entirely, Asians would be the majority at a lot of universities. There is already considerable resentment that Asians are overrepresented in university enrollments relative to their numbers in the general population. I believe these issues surrounding race and class and affirmative action all make Lin an intense focal point for larger cultural issues in America.