I can't write synopses. Rather, I can write them, but not in a manner that works for agents and publishers.
Query letters are a drag, but I can manage them. One doesn't have to tell the whole plot in a query letter. We can pick a single character and a major early catalyst and make an interesting hook to draw in an agent.
It doesn't work that way with a synopsis. There we have to tell about all major characters and plotlines, and give the resolution of the story. Since my stories tend to be very complex with many plotlines and several POV characters, I find writing a synopsis to be so difficult as to be not worth my while. So, when an agent or a publisher asks for a synopsis I simply don't bother submitting to them.
I'm sure that makes them happy. With their shortage of time and huge slushpiles, I am sure they are quite happy not to have my novels adding to their work. I can't help but think, however, that the perfect agent or publisher might be out there and I won't hook up with them simply because they demand a synopsis.
Angry Robot publishing was only the latest such site that sounded promising. It sounded to me like they were really looking for the types of books that I am writing. They wanted a two page synopsis. My complex stories make it impossible for me to write a good five or ten page synopsis, so there is no way I will even attempt a two page one.