Is it pointless to bring up poor supervision during PhD viva? I should defend my PhD in the UK near the end of the year.

Unfortunately I fell into the class of horribly supervised PhD students - with an ill-defined research project and an absent supervisor who steered me into so many different topics of my field that I'm convinced my results chapters lack depth and analysis.

For that specific reason I seriously doubt the originality and the importance of my research work, which will be thoroughly assessed during the viva.

Can the internal and external reviewers be receptive about objective arguments related to poor supervision during the 3-4 years of research? Or are they bound to discuss only the contents of the thesis?

PS - This is not an opinion-based or a stress-induced question where I expect "don't worry" answers. I'm well aware a PhD is a self journey and one should cope with difficult supervision. The question pertains to the viva only.
I'd suggest that the viva is possibly the worst time to do this. Almost anything you say could be interpreted as whining and trying to deflect responsibility for any shortcomings. Many things you might say would be countered in the minds of the reviewers whether expressed by them or not. 

Whether you bring it up yourself or just reply to questions or comments with complaints about your advisor or others would seem, to me at least, as unprofessional. 

If you have issues about the performance of your advisor, make it a separate issue in an appropriate venue after the degree is in hand.