Is Manual really worth it?

I entered into the DSLR world in 2009 with a Nikon D80 and no idea how to use it.  A few years later I picked up a D90 - and a little idea on how to use it.  In 2016, I picked up a D7200.  I have a bit of an idea on how to use it, although it does depend on who you ask.
Along the way, I've gone from the full AUTO mode through Aperture Priority to full Manual.
Take this for example:

Histogram is not too bad.

One would say that is an interesting photo.  What an interesting perspective to keep the deck rail in focus with the gulls out of focus.
Truth is, I wanted it the other way around.  
Today, I was playing around with the many, many combinations of auto focus.  In this photo, the mode was full auto.  I let the camera decide what the subject was.  
I have to ask myself, if I'm that picky to use Manual Mode for speed, aperture and ISO, why go only half way?  Why wouldn't I also do the focus?
Normally I use only one of the focus points that the camera has.  Pluck it out of the center and press.  I have a pretty good hit rate.  I tried full auto just for fun.  I was experimenting with multiple targets.  I wanted to see what the camera would do.
Like this:

Most of the gulls are in passable focus.  This is an exception.  What I'm seeing after reviewing the shots is the camera appears to be confused by the water waves.  I think because of the number of moving targets, the camera ignored the water.  Against the sky, my hit rate was much better with a single moving target.
One of the tricks I've used in the past is to find a comfortable infinity setting and it with the auto focus off.  Realistically after about 15-20 feet you're in the infinity area anyway.
I believe in Manual Mode for taking the pictures.  I'm going to get there for the focus.