That would be my guess as well. I have seen cones used to discourage ICEing at other sites. Sometimes the cones are marked with signs or stenciling to make their intent more obvious.
[Side note- feel free to offer me your wisdom and insight: As a matter of etiquette, I have currently decided to use dedicated stalls whenever available, despite mixed feelings about the consequences. Using a "shared use" stall does leave more dedicated stalls open for my fellow chargers, but it also has the effect of blocking an ICE vehicle from legally using that stall when I have a dedicated stall available. I still believe I should offer courtesy if I expect to receive it, unless it's clearly already a hopeless situation. Expecting an ICE vehicle to move within 30 minutes might already be hopeless. N.B. No reference to discourteous partisan politics intended. Originally, anyway. Honest! .........darn, honesty, another old-fashioned notion.]
I guess I hadn't thought much about it. I guess there are so many variables that would influence the decision as to whether to park in a dedicated spot or not.
Location of the SC would influence the choice. If, like you say, it is unlikely that an ICE that parks there would be back in 30 minutes, I might park in the 30 minute spot. Places like a sit-down restaurant or shopping mall, for instance. If the SC is at a travel center or fast food restaurant, maybe the dedicated spot would be better, since they can get their business done in 30 minutes.
Sometimes the design of the SC might influence my decision. Some have back-in stalls as well as back-in stalls. I try to use back-in stalls to leave the pull-in open for those who need them. That might influence me more than worrying about an ICE having a parking spot.
Charging traffic would override my concern for ICE driver convenience. If the only unpaired stall is in either the dedicated or 30 minute stall, I'd use it.
Obviously if there are cones blocking some stalls, and others were open, I'd use the open ones. Obviously, because that's what I did.
I suppose I'd use the dedicated stalls if I knew I was going to be charging for an extended time.
Honestly, I hadn't thought about it much, since it's still fairly rare for me to see other Teslas at Superchargers. We generally travel mid-week, don't visit populated areas, and travel during the day. I don't think the advent of the M3 will change that very much, since they will be even more likely to be Supercharging on weekends and close to cities.
I will say that I like the Superchargers like those at Aberdeen, with all pull-in stalls. I think they are much less likely to be ICEd
