It's to avoid getting fingerprints or dirt on them
You see, every so often, the Yu-Gi-Oh Trading Card Game ruleset is rather comprehensively revised
I mean, sure, youve got Rekindling Phoenix and Glorybringer or whatever, but to just shut off the vast majority of creatures indefinitely
Lotleth Giant chumps all the other versions of this effect simply by dealing the damage immediately, instead of filtering it through an easy-to-remove creature that needs to connect in combat
In fact, what made these rare cards rare was specifically the fact that these ability were "off-color." Equivalent versions in the proper colors show up in the set at lower rarities
2 slim booster packs randomly of the following sets: Eternal Beginning SV1, Miracle Journey SV2, Fearless Terastal SV3