I'm not sold on the idea that a sling strap connected to your camera's tripod mount is dangerous. Many tripods can be configured to put the camera at almost any angle you can imagine and camera companies know this. I have to assume that they would make a contact point like a tripod mount strong enough to secure the body as well as most lenses, at least those lenses not heavy enough to warrant their own tripod collar.
Tripods don't swing and bounce and twist around for hours at a time dangling their cargo upside down from them. The physics involved in a mass bouncing from below the attachment point vs. sitting atop one in a very steady state are much different.
I look at a neck strap connector and they just look small to me and I don't think they were intended to be swung, bounced and twisted either. (at least not as much as a sling strap would cause) I also don't think one neck strap connector is meant to be used without the other.
You could probably pull a car with one. I'd be willing to bet that the manufacturers take all factors into account and WAY overbuild the amount of stress a camera strap lug on a camera can handle. I've emailed CanonUSA with the question to find out.
You have a good point about the bouncing and swinging but not about the "just sitting on top" as I mentioned, many tripods can be configured to hold a camera vertically or even upside down, some are even desinged to be strapped to the outside of a moving vehicle and camera manufactureres know this. It would make sense that they would make that connector strong enough to support the camera in those instances. I'm not saying that I know they do, just that it makes sense that they would.
Right side up or upside down or sideways isn't the issue - it's all the rest of the movement for hours at a time while walking around that is the issue on the stress point(s).
It's like those machines that slam a car door all day long in stress tests. How many times can you slam a car door before one of it's stress points fails? 10,000? 100,000? 1,000,000? 1 Gazillion? It doesn't matter how well it's made - it has limits and something will fail at some point, if you keep at it long enough.
If a tripod mount on a body or grip is made primarily to handle the stress of several pounds of camera, lens and grip sitting motionless, with occasional movement and occasional additional stresses from vibration because someone mounts it to a suction cup on a car, that's one thing. It's a whole nuther thing to attach it to a 300' long bunjee and start throwing it off a bridge over and over and over and expect that it will never fail. Somewhere in between those two things are the stresses caused by a sling strap and walking.
Show where even one "tiny neck strap connector" has EVER come off a SLR or DSLR camera body that wasn't a cheap plastic POS camera.
I've been shooting for over 40 years, and that is one kind of damage I've never even ever heard a rumor of. Not once.
Can you show me where a tripod mount connected to a sling strap has has failed? Not this "my cousin's brother's sister's friend knew a guy" stuff. I'm talking about you or someone you've known in your 40 years experience.
You misunderstand. Unlike the sworn first-person testimony required by some, I'm willing to entertain 3rd person accounts. Just point me to one. I've never heard ONE. Not ONE. Did I mention the number is NOT EVEN ONE? Yeah. Go for it.
I think you're WAY reaching on this one...
I'm not trying to justify one type over another or anything, I'm just stating my observations.
According to your posts, you're relatively new to all this. But hey, maybe you have a degree in physics or engineering you can bring to bear on this issue? Or maybe you have someone at one of the major camera manufacturing companies who can fill you in on the details of their stress tests (I've already emailed Canon about the neck strap lugs - hopefully we'll have a comprehensive answer on that soon - I'll be sure to share with the group).
If you have facts, use them. I love to learn new stuff.