One of my fav albums, so Ill try and explain the appeal.
First off, I don't know if you are a guitarist but the guitar work on the album is severely underrated. Some really cool unconventional playing all over this album. Really great stuff, trying to learn a few of these songs is a fun time because most of the time it's cool to try and crack the nut of what Denison was doing.
Albini's production is perfect. Like, actually perfect. Every instrument is crystal clear. The rhythm section is heavy and hits like a truck. Makes the southern groove they carry sound that much better. The guitar tone is simple but perfect, and cuts through the mix like a knife. The band are at the top of their game and they sound like it.
Yow's vocals are perfect. Note that he doesn't consider himself a singer but rather a "vocal stylist." He always sounds panicked and spastic in a way that affects the psyche of the listener in a unique way. It isn't melodic, true, but hearing the yelps and shouts of a man who sounds like he's too terrified to be coherent over such a demented band is exhilarating in a way that is completely unique to the Jesus Lizard.
Once you acquire a taste for Yow's vocals it'll all make sense. Imagine how difficult it would be to get into a recording studio and convincingly sell the panic of sounding like a man being brutally tortured. Seasick, the song you mentioned, is one of my favourite performances of his. The guitar simulates being thrown around violently by a raging sea as Yow alternately panics as he realizes "I CAN'T SWIM" and tries to convince himself "I CAN SWIM" in a futile attempt to fight for his life. Really vicious stuff. Not to mention the part where the band simulates going under the water when Yow yells "AND TAKE A DIP" is basically genius beyond words.
Here's a video where Yow gets a bottle smashed on his head during a performance and gets up only minutes after to keep playing.https://www.youtube.com/watch?v=Uu9lUbf5GQ0