Ok, so I read through that link;
1) So one poster mentioned that in a class they had a problem with 8 scopes, and ~3 of them used vertically split rings. But that still leaves 5 scopes with conventional rings that had issues. So on the surface, I would lean more towards: bad scopes, improper mounting, etc. Not impossible for it to be the rings.....but I'm not convinced on the surface.
2) There a video of a guy tightening warne maxima (not the tactical type, although the only real difference is the tactical rings can be removed from the rifle while the scope is still held in the rings) rings onto 2-piece bases with solid rods clamped in them. He tightens the rings bottom screws first, then tightens the tops ones (like you should) and then the rings slide on the bases. Now....it's possible the issue is with the rings, however, what occured in that video should not, theoretically, be possible as once you tighten the lower half of the ring, That's what clamps it to the rail. Then when you tighten the top screws, it clamps the scope. If it moves after that, either the ring dovetail is machined wrong (too big), OR the base is too small. If you tightened the base screws until the two halves have bottomed out.....it's not possible for them to separate at that point.
3) From spending a LOT of time around new shooters and 'experienced' shooters.......I wouldn't trust 95% of shooters to correctly mount a scope (let alone use it properly). I also wouldn't
trust 75% of scopes I see on the market for anything other than fun (and admittedly, I don't own any NF or S&B scopes

)
4) When we are talking about vertically split rings; are we talking about Warne style where you fully tighten/bottom out the bottom screws and then tighten the top screws? Or are we talking about vertically split which are the same as horizontally split but rotated 90 degrees and/or vertically split with 'hinges'?