As Father Feeney famously pointed out, BoD requires an ardent desire to receive the Sacrament. But BoD can make you desire it less ardently, because of the complacency that, "oh well, if I die now, I could be saved by BoD anyway".
There's a rather disedifying story about Archbishop Lefebvre. +Lefebvre, having visited a missionary area, as he was leaving, was acosted by a native who asked if +Lefebvre could baptize him, since he was worried about not being saved if he died before +Lefebvre's next visit (which was some time off). See, if that were me, I'd be like "this man has more faith than most Traditional Catholics" and then baptize him right there. But +Lefebvre told him not to worry about it because if he died before then that Baptism of Desire would take care of it. So ... by telling him this, it turned a zealous desire to be baptized that if there WERE a BoD, that's precisely the kind of zeal and ardent desire (and intention) needed for it to take effect. But now this poor soul, having "relax" ... would have stopped desiring it with the same zeal as before, and quite possibly jeopardized his ability to be saved by BoD (if it existed).
Again, +Lefebvre was undoubtedly acting in good faith ... but he too had been poisoned by centuries of attacks on EENS. He was no theologian, never trained as such ... but I'm sure that he learned this stuff from teachers whom he respected as otherwise quite Traditional and conservative. Karl Rahner remarked with amazement after Vatican II that none of the conservative Fathers had made so much as a peep about what he (rightly) considered THE single most revolutionary aspect of the "Council", namely, what he euphemistically referred to as the "increasing hope of salvation for non-Catholics". While many conservatives excoriate Rahner for his notion of "Anonymous Catholic", where he holds that people can be saved BY Christ and the Church even if they are not IN the Church. Welp. +Lefebvre held the same thing, where in his "Letter to Confused Catholics" articulated the same thing, salvation for the "Anonymous Catholic". Incidentally, Rahner was criticed by the more rabid Modernists for holding that it was still BY Christ and the Church that they were saved. So, yeah, this would explain why nobody noticed. Well, Rahner noticed, and he was right. ALL the V2 errors are rooted in this single fundamental error. It is in fact, in terms of error, the "One Ring to Rule them All", and THE theological "Rosetta stone", as it were, to interpret all the V2 errors.