This is not entirely true. The poor may value their time like anyone else, but they often have a very different grasp on the time/money tradeoff. Not having money warps the value of time since (for the poor) lack of money is acute and how much time they have is abstract.

Anyone who has grown up poor or known those who are poor has seen this in action. People will go to great lengths to not spend small amounts of money to the point that working for minimum wage would take less time to cover the expense.