^ I think you just have a lack of info. Lucas is REALLY good. Dair is too good for damage output and combos, and Lucas is a versatile character who can switch between defence and offence really well. Much better character than Bowser. It sucks extra for me because I've recently discovered new things that have made my Lucas incredibly better, but the infinite grab makes it sort of worthless.
Now for the Marth grab..... yeah I think it should be banned because of how gamebreaking it is against those 2 characters by giving them animpossible matchup. Other characters who are worse off as far as ability may have bad matchups as well, but they dont have any impossible ones... thus these worse characters are suddenly MUCH more playable in tournaments yet they are worse. Just ban the infinite re grabbing.... this means marth STILL gets free struggle damage and a clean forward smash.... just not an instant stock and insane time to stock count advantage.
Now, even if the grab doesn't get banned.... I'm still gonna play Lucas, it just means I'll have to do it in a double blind pick, or on my counterpick after the opponent selects someone other than Marth... but I will be forced to play other characters during the tournament or eat insta death.