I'm in the US, reasonably up-to-date on blues in general, and this is the first I've heard of Seasick Steve.

There have always been and still are plenty of players, amateur and pro, who can do a credible job playing the most basic kinds of blues music in a "primitive" style. How "good" a given performer might actually be is generally moot ~ it's simply a question of whether you enjoy and/or are impressed by the performer's personality, which always comes through any musical performance, and especially so when said performance is so very simple and unadorned that there is very little to hear and to notice except the human feeling embodied in the artist's delivery.

Of course, the critical question is how many listeners come away with a strong positive impression. Performers capable of eliciting a good response from most of their listeners stand a decent chance of making a mark ~ and, with luck, maybe even a living ~ with their music.

Since I'm at work, with no speakers, I haven't witnessed any of the performances submitted to this discussion by Steve's admirers. I have a strong hunch that my reaction would very likely be "Nice enough, but I could do the same or better."

I very strongly suspect that Steve's greatest talent lay not in his musicianship but in a rare knack for self-promotion. I have no doubt that he's "got something," but so do countless others of us, stuck slaving away at boring day jobs and singing the blues only because we just plain can't not do it.