I suppose I understand your (and others', here) point of view. It's a different experience for me, grading-wise, not because receiving my grades is stress-free, but more because I'm never expecting it - so I don't think about it too much, just live my life, and when that e-mail comes, I check things, and it's done with. It's a superior experience than waiting for a specific day, or time of day. But, of course, that's my experience.

Perhaps a solution would be for these school portal systems to take this into consideration, allowing students to pick how they prefer their grades to be 'released'/delivered - 'unexpectedly', or on a timed schedule.