Within Judaism Satan is an angel on G-d's side, so it also makes no sense from this context, but most Satanists don't identify with the Christian Satan. A lot are, in fact, atheists.
Why wouldn't it make sense? Jewish Satanism would then basically be venerating YHVH's destructing aspect, but not be in opposition to him.
I think I encountered some whose incorporated such into their beliefs, but it is rare.
Satanism is a satire of Christianity, the Satanic verses and Satanic Bible are satire too. that's what Satanism is all about.
No.
Satire is certainly a part of it, but not the main purpose, mostly a tool.
I don't understand why anyone would willingly choose to become a Satanist? We all know that The Bible clearly states that - spoiler alert - Satan will be defeated in the end and all his followers will be tortured and / or destroyed. Why would you willingly join the side that you already know will lose?
It was already explained by other users here in general terms, but since Satanism is a manifold religion I'll also describe my own reasons behind it.
In my case, I don't exactly believe in the Christian concept of Satan, or in hardly anything of Christian theology at all. There are Satanists who do, but they are rather the exception.
What I do believe in is a kind of deity, or principle or force, which I decided to call Satan (besides a lot of other names) due to mainly two reasons:
- I've read a lot of texts written by other Satanists and what they seemed to describe as Satan tends to share many similarities to the deity I venerate.
- In the culture I live in, Christianity is the main religion (although atheism might be more wide-spread; I'm not in the US), and so I'm more familiar with its myths than with those of other religions. Also, I noticed that pretty much everything that Christians would call the work of the devil seems to be a comparatively direct manifestation of aspects of my deity, or at least subjectively feels like it.
As a pantheist, I believe that my deity is in pretty much everything, so that last argument might sound pretty pointless, but I differentiate between more and less direct manifestations of it (e.g., one's own innermost will is a very direct manifestation - other people's will influencing one's own will is much less direct).