Spammers are so annoying!

I am wondering, why spammers, bother to try to spam? Don’t they know most of their comments go into spam, and are never seen by us?
Why bother to spam at all? I hate having to go in and see what is in there, just in case I miss anyones comment, or it went into spam by accident!
I check the spam folder regularly now, just in case!
Good thing I did check it this morning, as there were 3 comments which weren’t spam, in amongst the 50 or so which were!
Its just so annoying! I think all bloggers should check theirs regularly! I’ve had issues before with comments that were legit going into spam and I don’t want that to be happening!
Do others have issues with that too, it cant just be me can it?