YES, LIMITED EDITION WAIFUS!!! GET THEM WHILE THEY'RE HOT!!!

On a serious note, Discoceris, I think you are overestimating the "scraping and struggling" idea. As you said, a lot of event maps, you either are going to clear them with your current team or you're not. If you give it a shot and get wrecked, banging your head against the wall is obviously futile, so go farm, level and come back a week later. Since events run every 2 weeks, no point wasting stamina on failed runs when you can take a week to power up and come back and get a respectable 2 slot, 3 skill event unit. There is very rarely a point where a few extra levels from a few hours of farming is going to let you clear a map you failed, so taking a couple days to level up and then come back for revenge is much more preferable.

So basically, your argument has merit IF AND ONLY IF you're addressing players who think a couple levels will make or break their ability to clear event map X, and I at least HOPE most players aren't silly enough to think one great hour of leveling will let them clear a map they just got wrecked on.