A good performance, especially one that fits the setting they're going for, can make a lot of complaints vanish into thin air. The issue with the current Kermit is that the voice just feels, bored? It lacks an Energy that Henson and Whitmire had. He feels too much like a Boss character and not much like a friend.
When I see a performance done by Whitmire and Henson, he feels like a friend, Kermit feels like an alive, dynamic character, when I see the performance done by Vogel it just feels flat, and it's disappointing because Vogel is a good performer, he's just not the choice they should have done for Kermit.