Keyword stuffing is extremely unpleasant because it makes your content look unnatural. Also the thing about keyword stuffing is that SE's regard it as a black hat
SEO technique. Thus if its really not going to serve you well in anyway, why use it? It's best advised to use keywords effectively in your content so that it is optimized. Couple of things about keywords:
1) Accurate keyword research must be done
2) Create unique content optimized with keywords
3) Maintain the desirable keyword density
It helps to use SEO experts to get this affected correctly for your website.