The main duties of the Lords are to impart wisdom and delay bills. On the whole this is a good thing, and it is unclear what benefits will come from being democratically elected.
In theory they are completely wrong, in practice I only see them doing good things.
Nobody argues that juries should be elected, or selected by the police.
Heredity as it is (or rather was) favours white, male (many of the titles couldn't be passed to women), upper class, privately educated, wealthy, christian individuals.
http://www.publications.parliament.uk/pa/jt201012/jtselect/j...