Why is the Yamaha Virago seat so uncomfortable?

This is why. Look at the metal rib they stick right down the center of the seat.

If you flip your seat over and look at the first image. You will notice the
two stress marks in the plastic. This is cause that metal bar ends right in the tailbone area
and your butt is trying to push that bar through the plastic. Find your self a miss shaped
steal bar; bent so it is solid and ridged and stick it under your couch cushion for a while.
And after a while you will pull it out, well do the same thing to the virago seat.

At first I just cut a small square in just the tailbone area and remove a small hunk of metal.
But I quickly removed the rest..
I drilled out the last 4 rivets and yanked it out with some pliers.

I do not even know why they did that, the bar is too big; odd shaped and to
have it end in the tail bone area; so you are sitting on the end of the bar with
just a few inches of cushion between you and your butt is just uncomfortable.