More Dimensions are Not Necessarily Good

The main problem is that almost all 3D systems require you to wear those goofy 3D glasses. Some use paper glasses with plastic strips, some use high fundoo glasses that look like something straight out of 'Mission Impossible 2', but the point is that you have to wear those glasses. It is hard enough for a person with normal eye sight to wear them; I can't even begin to imagine how hard it will be for a person who is already wearing glasses to correct their vision.
Another issue is that most of the times, the picture, maybe because of the glasses or maybe because of the projection/rendering look very dull and dark. There will be blurred patches everywhere and most of the time; the colors will be all messed up - especially with the red/cyan glasses.
Yet another issue is that there is no one fixed standard for 3D - some use polarization, some use shuttering, some use some proprietary standard (like the Nintendo 3DS).
So, the point is - 3D is a BIG mess. At least now it is. So, until a good 3D system comes up which does not require me to wear those horrible glasses and which can provide me the same detail and color definition that 2D gives, I will be sticking to HD movies on Blu Ray.