I think a lot of all of this is just a bit of era/model snobbery than anything else.
OK, I'm a snob. Probably stems from the era I grew up in, when the very idea of putting a lock on a loaded gun was considered UNSAFE, and the idea of a lock IN the gun was ridiculous.
One locked the gun IN something, one locked the ammo IN something, preferably a separate something. FOR STORAGE.
Then some bright fellow came up with the trigger lock, and oh, gee! Now I can load my gun, and put a lock on it, so its "safe". Blithely ignoring the fact that putting anything on or around the trigger of a loaded gun = unsafe.
And, if its not loaded, why bother with a lock???
The internal lock is mechanically safer than a trigger lock, I just object to the entire concept. If you load a gun, you do it because you believe it is possible that you might need to use it, without any advance notice.
I feel an unloaded, unlocked gun is better than a loaded locked gun. I think it would be easier for me (at least) to get some ammo in a gun I needed in a HURRY that it is to find, and then manipulate that little key. Especially if that key in on your key ring, hanging on a hook in another room.
A matter of perception and priorities, I suppose. I'm not in a situation where children or random strangers do not wander through my house unescorted without committing the criminal act of breaking and entering.
I see the requirement for a lock as a form of tyranny. In the way that tyranny is "new" and additional regulations. What one grows up with, one considers normal, and generally right, and proper. Its the way things are.
Go beyond that and its imposing extra burdens, without consent. (and to me thing includes the tyranny of the masses inherent in democracy) That's a form of tyranny. Maybe its for my own good, as THEY see it, but if I don't get to decide that, for myself, it's tyranny.
Seatbelts and helmets, even background checks are good ideas and one should use them, but I don't think they should be LAWS, because they weren't laws when I came of age, and just seem like an extra way for the govt to pick my pocket if I exercise my free will in a direction they don't approve of.
I do make a distinction between those kind of "safety" laws and the consumer protection type that prohibit people from cheating others, defective products, and so forth.
Now, if you are younger, and those laws, and an internal lock on a S&W have been a constant your entire life, you look at those as the normal, right and proper way, and think old coots like me are off our nut to have an issue with them.
Eventually those of us who remember when we had greater freedom to use our own judgement will pass, and no one will have any problems with what we've got now. I can't legally do a lot of the things my Grandfather could, and I expect my Grandson will be in a similar situation, though its likely he'll never realize it.
sorry for the rant, but locks are one of my "buttons". Not the lock, per se, that I can ignore, but the belief that they are needed and I'm somehow a danger to others if I don't have one....