Like the rsd guys say, his voice is why people listen to him, not his content. A whiny pathetic warbling voice is irritating an unauthoritative. Shows lack of confidence within a male hierarchy. People would instinctively categorise his opinions as less important. Luckily he has a privately educated RADA acting school voice like many famous actors.

I recommend studying the film 'Beckett' personally with Peter O Toole and Richard Burton. Patrick Stewart and Brian Blessed also attended RADA (Royal Academy of Dramatic Art). Its a combo of gravely voice, altering tonality high to low, altering volume for emphasis whilst speaking and pausing dramatically.