Well, that will depend on what you want to do with the language. If your intention is to read Manga and impress others with your being able to speak the language, it is not necessary. If you want to work for a Japanese company, it is not absolutely necessary, if you write Japanese and make mistakes, you would still be viewed favourably by Japanese because you are trying to write their language and your mistakes would be quickly forgiven. If you want to master the language, show respect to Japanese people by studying their language thoroughly, and see a "wow-face" on Japanese new acquaintances when you ask them their name and then proceed to write it correctly... then, yes, you need to learn how to write kanji.
To be honest, learning how to write kanji properly does not take much effort, at least not as much as it seems to be required. I suggest you buy a Nintendo DS and buy a game called Bimoji. That game helped me a lot.