They see a need to provide users with some anti-malware software (at least long enough of a license term that the user can select the malware product of their choosing).
Granted, bundling malware can help generate sales for the malware vendor used, so they offer it to system vendors at very little cost.
But their workstations don't come with all of the crap that the consumer systems do.
In terms of PSU, most vendors use around that particular wattage rating. And when used with a single GPU, it will be fine (can be a problem if a second GPU is added, depending on the card, as well as other cards in the PCIe slots).
PSU design, QC, and parts selection matter greatly in terms of it lasting (i.e. if it's Active PFC or not, if it has sufficient capacitance, if they can take the heat, ...). Even what the rating is matters (peak vs. continuous/nominal value). For example, a 500W PSU that's it's peak rating will only be able to deliver ~350W continuous. I suspect this is what you've probably run into, as most ratings are peak values if it's not explicitly stated as continuous/nominal power ratings.
When comparing true workstations and the PC variants come in cheaper (same Xeons and use ECC memory), then those comparisons are valid.
For example of a valid comparison of SP models (Xeon based workstations), take a look at post #39.
Comparing the MP to various consumer based PC systems definitely aren't valid (which unfortunately, does tend to happen when the price issue surfaces).
