LogFAQs > #961760649

The thing is in almost every other CCG, "bad" is subjective because there are all kinds of tradeoffs involved -- maybe a 1/1 monster costs less than a 2/2 monster, or have an ability, or had a different cost (blue mana instead of red) -- so you're less likely to have things that are just worse versions of other things. YGO's cost system heavily had strictly worse versions.

It was even more glaring in the early game where monster levels only mattered in terms of tributes. Later on, card effects meant that a lv5 was sometimes a lv6 despite both usually requiring 1 tribute (ie, legendary ocean which meant lv5s could be played as lv4s, skipping a tribute)

I'm going to say a large part of the problem was that YGO probably wasn't designed as a CCG -- or, at least, not as a real CCG. I'm pretty sure it first appeared in the manga and then the popularity led to adapting cards that simply appeared in the media, and the overall philosophy from the early game ensured a lot of useless cards got developed for no good reason. That kinda changed as the game continued, so there are fewer just absolute crap cards today.