A big reason Calvinists criticize Arminians is they think Arminian theology gives man control over his salvation because Arminians think man must exercise faith in Christ. They also think this entails man working, in some way, for salvation. This is not to mention all of the theological nuances that exist in each system (i.e. Calvinists also believe man has to have faith but it is caused by God; whereas Arminians think faith is a response to God's prevenient grace).
But, I have a question for my Calvinist brothers and sisters. They claim God determines everything that happens in a proactive manner, even sin, yet without God being responsible for that sin somehow. They also, as I stated, believe that faith is caused by God in the same manner, and He gets all the credit for that faith. Their concern is that man not claim credit for his faith. Here's the rub: how can God determine sin and not be responsible for it, yet at the same time determine faith and be completely responsible for it?