Guy who has been in competitive Yugioh for 6 years here.
There's many, many reasons why even competitive players hate the game, but to get to the point:
>Management
-Konami is the WORST company you could ever have in charge of a tcg, maybe just behind Bushiroad
-Konami insist on having favoritism in favour of Japan versus other regions, making a very bizarre herarchy of Japan > USA > Europe > LATAM > Oceania > China, in many aspects
-Cards are released on low rarities FIRST on Japan to push sales since costumers over there don't bend over, then the same cards are release 3 MONTHS LATER on usa/europe with upgraded rarities in order to push sales by making costumers pay more.
Think of Flamestrike being common on Asia servers, and then being Legendary on usa and europe, that's literally the case for any value card.
-Kevin Tewart (head of konami in USA) usually changes the name of card to "le wacky family guy humour XD" type of things because he simply doesn't like japanese references.
-The same person abuses his power by pushing exclusive cards for america, while sabotaging the perfomance of decks released by japan on USA
-Several members of Konami in america have insulted and ridiculed players on social media over questions regarding dates, mechanics and fucks up, and never apologize
>The banlist
-Konami uses a list that bans, limits or semi limits cards from the game, which they use to push new decks from new releases to be over the top, and push down older decks after they have been already sold
-Konami of america insist on making secret the date for said banlist, while making several per year.
Meaning you can literally buy a deck today and there's the posibility of tomorrow having a banlist making your whole purchase useless.
>Gameplay
-The decks being pushed right now are all like Miracle rogue on steroids, and games rarely go beyond turn 3 to 5, due to said decks ALSO being OTK machines