No it is due to the confusion about what the BB realy is and is not. If you happen to think (as is often popularized in media) that the BB means : the (absolute) begin of space,time and matter, yes, than in that case there is "nothing" before the BB.Perhaps my information is out-of-date.
However, apart from the fact that such is an ill metaphysical position (supposedly "everything" came from "nothing"), this is not what the BB theory realy says. The BB just says that the universe was in the far past denser, smaller and hotter. And this is (mainly) based on predictions or solutions to the equations of GR, but which introduce the difficulty that they also produce the so-called "singularity". This ought to mean also that GR predicts it's own break-down (i.e. it can not make predictions of what happens there) near that "singularity". So that "singularity" is just a theoretical point, not the actual point in history in which the universe "began". What cosmologists need is a theory (i.e. a theory of quantum gravity) that can both deal with GR and QM, since both fundamental theories are of importance there and they are to-say not on "speaking terms" with each other.
The whole issue of weather or not time can be said to have a begin (without time, how can anything be said to begin or change?) is however something that is more properly attributed to philosophy.
I would think, most cosmologist would see time as eternal, yet this is appearantly not always the case, and not all models are ruled out by definition that have time begin somewhere.
This is a very "old" philosophical problem (can motion/change arise out of a state of motion/changelessness?)
For cosmology, the only thing of importance if is if such a model makes the right predictions, that can be experimentally tested for (observed).
What the initial BB theory could not explain is why the universe is so flat and why the universe is so homogeneous. Inflation theory could explain that.
Other candidate theories are ekpyrotic universe model, developed in string cosmology.