Well if you would show only physical damage as dps then spread sheet also would be simple and much more accurate.
So your solution to a common spread issue is to make a totally inaccurate sheet?
For weapons that have an elemental damage bonus, that elemental damage can easily be 20% to 50% of the raw damage. So leaving it out would be rather .... odd.
And yes, tougher enemies tend to have tougher resistances. But a majority of tough enemies have at least one weakness, or low resistance.
So rather than having a highly inaccurate DPS spreadsheet, having a single spreadsheet that lists raw DPS before various factors is much easier. And rather common across games.
As for player confusion, it seems most players are aware that raw damage is before defense, resistance and other factors are calculated. However, it would be fairly easy to add that type of statement to the current sheets just to improve clarity.