Nowadays,it seems that people are especially keen on sports events. For instance, people are willing to pay for NBA or Olympics. So Compared to the people in other important fields, successful sports players can always earn far more. (第一句和第二句的逻辑关联没有叙述清楚)

Some people think this is unfair （什么事情unfair没说清楚，所以可以用this代替it，this指代第一段所说明的现象）especially when they see a famous sports star can easily earn a great deal of money through a advertisement unlike people in other professions like office leaders ,famous scientists and the politician.（没必要罗列重复）（可以直接用从句接）who are really benefit(benefit本身是动词，前面不能加be动词) for our society（这么长句子一口气不够用啊）.However,（这里的转折用however表达并不恰当） their effect do not get a good return on their rewards. （逻辑有问题，难道运动明星对社会就没贡献吗？）
Those people who think this is fair hold an opinion that though a successful sports player can earn much, they did put lots of effect on their jobs before they succeed.Actually many famous athletes have lots of injuries which are harmful to their health .In the other words,they use their health in exchange for the high price paid. (读到这里已经一口气不够用了可是还木有断句) Meanwhile, those famous athletes like Yao Ming ,Kobe Bryant they often use their influence to do charity work and help those people in the poor area or some disabled （和charity work重复，而且是charity work的展开，中间用and不合适）.This is also a way to benefit society. （与前面office leaders才真正对社会有用的观点相矛盾）（并不是所有运动员都受严重伤病的困扰，此处把伤病描述成“伤病威胁”更恰当）
In my opinion ,I（I任何时候都要大写） think this（this指代性更强） is fair（faire和justice同义词可是意义不一样） because theysport players （这里不能用they指代，因为这段前面并没说they是谁）should（用should不合适）can be under huge pressure which common people could not imagine. and at the same time, it indicates that our society put much attention to sports than any other fields(真的比所有领域都重视吗？).（最后一段的两句话之间的逻辑没有叙述清楚，运动员压力大为什么说明社会对运动注意力更多了？而且这段话和主题并没有直接关联，如果有，也没有叙述清楚，而且不应该放在最后一段叙述，最后一段应该是总结前文，强调之前的观点）