In my opinion, the real problem is that with virtually every expansion Blizzard takes some classes very seriously (giving them new archetypes and strong support cards for existing ones), while treating others like garbage. For example, how can they print cards with huge potential but without any support, making them virtually useless (e.g. Archwitch Willow)? Yes, these cards may be playable in a few months (along with subsequent extensions), but they might as well never be playable (which actually has happened couple times in the past, because Blizzard simply abandoned previous ideas, leaving some classes with dead cards until the next rotation...
This usually leads to situation, where some classes become more powerful and diverse with successive expansions, while others remain weak and have virtually no representation in the meta (some classes wait even several months for their turn to shine, which is sick!). This in turn, makes the meta stabilize faster and the game faster becomes boring and repetitive. Fewer playable classes in the pool simply means less choice, less variety and less fun.
In my opinion, the real problem is that with virtually every expansion Blizzard takes some classes very seriously (giving them new archetypes and strong support cards for existing ones), while treating others like garbage. For example, how can they print cards with huge potential but without any support, making them virtually useless (e.g. Archwitch Willow)? Yes, these cards may be playable in a few months (along with subsequent extensions), but they might as well never be playable (which actually has happened couple times in the past, because Blizzard simply abandoned previous ideas, leaving some classes with dead cards until the next rotation...
This usually leads to situation, where some classes become more powerful and diverse with successive expansions, while others remain weak and have virtually no representation in the meta (some classes wait even several months for their turn to shine, which is sick!). This in turn, makes the meta stabilize faster and the game faster becomes boring and repetitive. Fewer playable classes in the pool simply means less choice, less variety and less fun.