I think most physicists consider the universe to be 11-dimensional at the moment
Very few consider this true.
Those that do only care that additional "dimensions" lead to a lot of very interesting things when they're used to model the world of high energy physics.
The word "dimension" means something very different to the average person than what it does to physicists and mathematicians when viewing it in regards to things like manifolds, compactification, Calabi Yau, AdS, CFT, gauge/connection, degrees of freedom, etc.
If you make the discovery that the exterior derivative of a uniquely defined two-form vanishes, the exterior derivative of its Hodge dual vanishes, and the initial two form is described as the exterior derivative of a very important "potential," you piss your pants and open your LaTeX file to start typing....whatever number "n" ends up being the orientation of your volume element.