Contrary to what you believe, I don't have a drawer full of forms for every possible scenario that I can pull out and email you at a moment's notice.
I need to know what you are trying to do. Then I need to think about how to accomplish that. This takes time and effort on my part. I'm not just typing your name into the blanks. When you do a one-off business deal, I am preparing a one-off agreement for you. I wish I had that magic filing cabinet with just the right form for you. It would save me a lot of effort. (But I don't want everyone at my firm to have it, because then I'd be out of a job.)
But thank you for asking me to take care of it, instead of just writing some crap yourself, signing it, and showing it to me two months later when you haven't gotten paid.
P.S. - Also? When you tell me how awesome I am for sending your completed contract in the middle of the night, I don't appreciate it. I am sending it in the middle of the night because I kept getting interrupted during the day and couldn't start concentrating on your work until 7 p.m. I would much prefer to be asleep right now, after spending the evening with my family. Please don't compliment me for missing out on that. And why are you still awake? Go to bed. You have a big day tomorrow.