Ogre got a bit of a critical review from Mike Acton a few years ago along those lines and since I believe they have re-architected things quite a bit. So I'm not sure from what version your comments apply, it is more performant now than it used to be.

It might not be the engine to use if you want to make Doom5, but some of the best selling games of all time of have been made in Java, or older versions of Unity, which have more performance limitations than Ogre.