I agree that using blackhat will be a burden in the future because once detected your rank will slowly decreases and worst you will get banned from adsense.
Blackhat is something I certainly wouldn't want to mess with. However, though, I think gray-hat is simply unavoidable. What is that? Well, as the name implies, it's not really correct, but not really incorrect either. Anyway, gray hat is unavoidable because obviously tons of sites exist with bad grammar, copied content, and other infractions yet rank.
white Hat SEO: In search engine optimization (SEO) terminology, white hat SEO refers to the usage of optimization strategies, techniques and tactics that focus on a human audience opposed to search engines and completely follows search engine rules and policies
Black hat SEO: Black hat SEO is a practice against search engine guidelines, used to get a site ranking higher in search results. These unethical tactics don't solve for the searcher and often end in a penalty from search engines. Black hat techniques include keyword stuffing, cloaking, and using private link networks.