Hi, feraligart enthusiast here, meganium was my first starter EVER bc chikorita was more aesthetically pleasing to me. And if i have to be honest, design wise meganium still wins.
Also, true pokemon fans dont hate meganium, they sob in her stead. Poor thing is a punching bag.
Meganium hate is tied to the fact pokemon was a game played primarily by little boys. Little boys think spiky Gators and fire-bears are cooler than flower cucumber. This is because they are correct.