I think it is a disservice to outright label people as anti-vaxers simply for questioning the risk-calculus of vaccines. The (1/7 million) is the current, unconditional and empirically observed adverse effect of the vaccine - this is a somewhat noisy measure of the true prevalence of this issue. It is okay to be cautious and there are legitimate concerns, and quite frankly, I trust the FDA have good reason to pause this if Moderna/Pfizer are readily available anywy. In countries where there are not alternative vaccines available, the risk calculations change, and as such, you might be better off taking J&J or AZ. In any case, to your earlier point of why they stopped it: they didn't stop it because (7/7 million), they stopped it because it was not observed in the trials and now they have to recalculate the risks for various age-groups and inform people, accordingly. If these events were observed in the trials and the prevalence was the same (in trial, and out of trial) then it would not be a cause for concern.
Edit: got the wrong agency, it was FDA, not CDC