Yes in my oppinion that does make you a hack. My oppinion is from an engineering point if view and if you had knowledge in the same field and were properly trained you would have that oppinion too. Adjustable wrench AKA 'nut f@cker' are tools for plumbers and electricians. Not for fitting. Use the correct tool for the job or don't do it. That is what I was taught. The same people that use shifters are the type of people that use loctite products where they should not be used. Belive me, I spend a good portion of my time fixing other peoples mistakes.
Butcher is a term used for someone that not only cuts meat into delectable cuts but also someone in the mechanical fitting trade who likes to use the wrong tools and cuts into or rounds off nuts - bolts, use wrong speeds on mills / lathers destroys cutting tools... And so on.
Op Perhaps you could just keep a few spanners of the correct sizes that you need for your equipment in your save a dive kit. There are not that many needed sizes as most sizes are standard.
Also Im guessing the op is not going to be doing this task on a boat with his emergency dive kit, so my advice was directed towards having a useable home toolkit. My advice is correct and there is no argument towards using a shifter over a proper sized spanner in your home.
You can do as you please with your own equipment, by all means use a shifter. But it still makes you a lazy hack if you could have used the proper tool. This is all my honest oppinion.