Why do publishers still print a 'Half title' page? Isn't a Half Title redundant, when the Title page already states the full half Title?   See Wikipedia:


  


I know why books must have blank pages, but why not leave this page blank? 

I instance The Happy lawyer. The front cover contains the full title The Happy Lawyer: Making a Good Life in the Law. Then the first Half title page states only 'The Happy Lawyer'. Just after p. xiii (The Foreword), but before p. 1, is another Half title pages that states only 'The Happy Lawyer'.

Another instance is Better Never to Have Been. The front cover contains the full title 'Better Never to Have Been: The Harm Of Coming Into Existence'. Then the Half title page states only 'BETTER NEVER TO HAVE BEEN'.
Why not?
It purely a stylistic choice.

Why bother having a title page at all when all the info is also on the cover/spine?

I think it is a nice stylistic choice since it gives an uncluttered first impression of the book