In any case, I don't think you were going in that direction, but now I'll ask you directly. Do you think SC leaves the door open for the political intention of attacking in the Summer of 1941?
Strictly speaking, yes. But only in the sense that his argument against it is not absolutely conclusive and definitive. It hardly can be, as he hardly addressess the issue at all on the political level, just on the level of military planning and military realities. To put it slightly differently, I think he conclusively shows that the Red army was not capable of such an operation, also that its actions in the months prior to the outbreak of war do not reflect such an intention. This is a very, very heavy argument, but it is not definitive, as it remains possible that a political decision to attack some time in the summer of 1941 nevertheless existed. Here Zhukov's proposal for a pre-emptive attack is a case in point - Glantz does not seem to realise that regardless of whether Stalin even saw this plan or not, the fact that Zhukov produced it shows that the state of the Red Army clearly did not in itself make a strategic attack an unthinkable option to the Soviet leadership. This side of the issue can only be satisfactorily addressed on the level of strategic and political decision-making, and as Glantz points out in his quite brief discussion of that issue, most of the relevant documentation remain unavailable.
However - this is little more (though also no less) than the appropriate academic reservations on a subject where the state of the sources are not everything that might be desired. On the strength of the very considerable information that is known, I do not see anything substantial that would support such an explanation, while there are very weight arguments and evidence against it. The conclusion to draw from this appears to me obvious, and is the same as yours.