I agree that we should not actually label them with "left" or "right". But they should be mapped in some way, and since software can distinguish left modifiers from right modifiers and show names like L_SHIFT, R_SHIFT in configuration dialogs for user-defined remapping etc, it is nice if they are mapped in a somewhat logical way.The left/right shift,alt,ctrl labels are just there to indicate correspondence to a normal keyboard, right?
I don't think we should actually label them as left or right. The important part is that there are two of them and that they are different
(and thus have different actions mapped to them).
By putting the Right/Rear version of all modifiers on the shoulder buttons, it is relatively easy to remember which one is which. It is also nice if the Left modifiers can actually physically be located to the left of the corresponding Right modifier, or at least not to its right.