This seems silly because a great portion of those of us complaining (I assume) are doing so because Glee is not what Glee used to be. Glee was what we wanted it to be (and then it stopped being that), and I'd argue that Glee obtained its present popularity because of how it used to be.
Regardless, Glee has not shown the crazy growth in audience (excluding special episodes) of other, more critically acclaimed series such as Modern Family. And on top of that, Ryan Murphy already has a track record of not sustaining a series for long. It's funny that you mention Smallville, actually; will Glee last 10 seasons (let alone half of that)?