Your last statement is patently untrue and should be corrected to state most knife aficionados that have not learned how to sharpen serrations tend to avoid them.
First, kudos to you if you have acquired the skill.
You undercut your assertion that it is patently untrue by adding a qualification. If it were patently untrue, no qualification would be needed.
If you spend time on BladeForums (and I suspect you have), you would see that most of the knife aficionados there who do know how to sharpen knives quite well nonetheless avoid serrations because they are a pain to sharpen.
So if you want to say that guys who
have learned how to sharpen serrations and who want to spend their time doing so don't mind serrated blades, you are entirely correct.
I have the Spyderco SharpMaker, and it requires a learning curve to use. It requires a greater learning curve on serrations, and I don't think most divers would be interested in acquiring the skill just to sharpen a dive knife. Using the SharpMaker with a plain-edged blade, it is easy to keep the factory edge sharp (provided you don't let it get too dull.) But even there, it requires practice (as evidenced by all the posts on BladeForum from newbies asking why the SM isn't working for them).
I will say that, with the amount of cutting that a diver is likely to do with a knife, it's unlikely that the Spyderco with a serrated edge will need sharpening.
And I think that any Spyderco Salt is superior to any folding dive knife with a Ti blade.