It's not surprising that many people have difficulty accepting the Vmcg problems which have been discussed above - very few pilots ever get to play in the Vmcg-OEI sandpit.
The observed fact is that, for operations very near to (the real) Vmcg (for the day) the onset of alarming lateral deviation is rapid and occurs within a few knots of Vmcg.
Like many, I wasn't convinced .. until I was involved in several test programs which looked at the specific problems on the runway ... I still have some VERY interesting videos taken from the runway head which display a "now you see it, now you don't" sort of steering problem. If I were a doubter before .. I became an INSTANT convert ...
The reason that several of us raise this problem in PPRuNe every now and then is for the reason that it is generally not understood at all by the non-test background pilot fraternity.
It's not a day-in, day-out problem, but some background knowledge might just save your neck some day when you are tempted to takeoff in a high risk situation .. when there may be an alternative option available.