Glock, if I wanted a Walther I would buy a Walther.
Pretty sensible answer, allowing for the brand names to be switched around to suit the preferences and desires of the potential purchaser.
Brand loyalists used to puzzle me, but now I generally just ignore them when they go on and on about why their preferred choice is "better" or "best". Everyone is certainly entitled to spend their money as they see fit. Why not?
Having been a firearms instructor for over 20 years, and having been to a fair number of various armorer classes for different firearms (17 factory classes, and a couple of non-factory classes, including many recerts), I've seen my fair share of things occur on live-fire ranges, and off the range, with most of the guns used for common defensive use/service.
I've also listened to my fair share of other instructors and armorers discuss their experiences, as well as having listened to many armorer instructors, repair technicians, gunsmiths, engineers, sales reps, folks who proctored "tests" of various makes/models, vendors & LE distributors, etc, listening to their experiences over the years.
It can be rather surprising sometimes to consider the range of experiences which can be heard from a lot of different instructors and armorers over time, too. It's not hard to find examples of the "grass is greener on the other side of the fence" outlook when getting together in a room filled with firearms instructors and armorers. Quite often you can find folks wanting to trade out of one brand/model to something being used by another agency ... who is just as interested in getting rid that make/model and going to what the other agency is wanting to get rid of.
If I felt someone made an ideal, perfect, does-it-all type of handgun which was infallible and would be perfect for all my needs, that's the only make/model I'd own and use.
I own and use a number of makes & models, though ...
I remember when my former agency was preparing to replace our existing, aging inventory with new guns. I carefully remained away from the actual selection process, leaving it to a pretty diverse group of folks chosen to conduct test-fire and evaluation, and the folks who evaluated their results and made the actual decision. I dodged all questions about my personnel preferences and remained impartial when helping proctor the T&E sessions. I made it fairly well known that I had no concern which make/model/caliber(s) were eventually selected. My only concern was that I had the training, tools and parts necessary to maintain, support and repair whatever was finally chosen. It didn't matter whether it was line level staff or command/admin staff asking me about my opinion. I basically told them to pick whatever they felt best met the needs of our whole agency, and I'd be on board with using it myself, as well as helping maintain, support and repair it, as may be necessary. (It became almost a mantra for a while.
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I stopped being what amounts to a "brand loyalist" a number of years ago, myself. Doesn't much bother me if other folks are that way, though. Different strokes ...