Simply adding a bunch of ranking keywords to your content is considered keyword stuffing, and Google ( and other search engines)  will recognize you are trying to “game” the system and and penalize your site.

In addition to search penalities when you simply add ranking keywords to your content instead of focusing on creating meaningful, quality content, you ill disappoint the human beings who come to your site.

Pages stuffed with keywords, will often see extremely high bounce rates and low conversaiton rates, defeating the purpose of drivin people to your site to begin with.