Probably told by a guy who wants to sell his engines!
I am not sure where the OP got the information, but I have told people that on several occasions. I think the generally heavy line tension of electrics is probably a liability in heavy, smooth air, and a perfectly-running piped engine seems to respond better than the Igor feedback system to help keep the coner speeds under control. I noted this effect at the 2015 NATS Top 20 day and 2015 Golden State where, in both cases there was about 20 mph+- but very smooth air. Both times, I had essentially no difficulty getting through with a competitive pattern, and never had any real doubt or concern about it. Particularly at the NATs, several highly-competent electric fliers came down rubbing their hands and having had to expend great effort to keep the airplane under full control in the maneuvers. Not that this really means all that much, but in both cases I came out on top for the day - highest two-score total at the NATs for Top 20 day (and David and his PA75 had the single highest flight {but got inexplicably killed on the other one to the point it was possible he would miss the flyoff}) and won the Golden State.
There are several problems with my theory, of course, the primary being that you have to have your system working nearly *perfectly* and that's not always possible - compared to electric which at least will repeat its performance regardless of any outside influences. I think my percentage of hitting that is much higher than average but it's not 100%.
Note also that the flip side is also true - while a perfect IC system might work slightly better than a electric in this small subset of conditions, I think electric works, generally, *much* better in dead air and hot conditions. There, the sometimes brutal line tension can be a bonus and again you aren't trying to fight the prop and the engine at the same time*.
In fact, I am so sure that this is the case that I am working on a new setup just for the case of dead air:
https://stunthanger.com/smf/engine-set-up-tips/alternate-ro-jett-61-setup/So far, so good on that one, and I think that all is required to switch to the good wind setup is change the prop and the launch RPM - not the pipe length, venturi, or fuel. In fact the needle is pretty darn close, if I switch to the baseline prop, leave the needle, the RPM pops back up to within 100 rpm of the right speed for that prop. It's a little touchy on the needle with the big prop, suggesting the pipe is a hair too short, but moving that would make switching back and forth much more difficult.
Note that this illustrates the other issue that will eventually drive everyone to electric - nearly all the adjustments are electronically-settable and infinitely repeatable, the only possible exception being the accelerometer tilt or skew- which is still a lot easier to do than change the pipe length or venturi.
Brett
*Same as a 4-stroke, actually, in that regard, but the 4-stroke is a huge liability and a handful in heavy air, far worse than an electric due to the nearly complete lack of accommodation.