Ever since the SEO industry grew beyond the in-house and homegrown webmasters and into a client consulting service there have been misconceptions about what SEO is, what SEOs do and the "type" of people that are SEOs.
The term "snakeoil salesman", and "woman", has plagued the SEO industry for years. The bad reputation that the SEO industry harbors is passed by word-of-mouth or by scathing news/blog posts about a business owner being swindled of their cash by the "scammers, spammers & hacks" that make up the SEO industry. We cannot deny the fact that these people do exist within the SEO industry or, to that point, within any and every industry on the planet. If there weren't, lawyers would be broke.