Wattage isn't the only factor in a PSU, as I'm sure you well know. They could be doing it without knowing, as we have seen companies do before, and are using PSUs with low quality rails, transformers, capacitors, etc. So many issues can arise from these subpar components, and inevitably could destroy the system. Not saying HP is doing it intentionally (although they very well could be), and I'm not saying it's definitely a low grade PSU. I'm saying it's a possibility, so I would rather trust my instincts and get another PSU from a company I trust rather than take a risk and assume HP used high quality components for all their parts and still sold it at that price.