Benefit of learning roots

I do believe there is definilty benefits in learning roots but my question would be more: is it for everybody?

I started to do English from the Roots up w/my 6th and 8th grader.

I thought my oldest would get how it helps to know the meaning of words you do not know by recognizing the roots. He really could not care less. His spelling is actually pretty good. He is terrible at memorizing things though so this root thing is just very frustrating to him.

Before this I would have him find definitions to new words he would come across. He liked doing that but he would soon forget the words he studied a few weeks before.

I guess what I am wondering is is there value to have him keep trying to memorize these roots? I am thinking if he goes on to College it would be good for him to get used to memorizing things. 

should I choose something else?