Every game has that one "cheap" weapon (noobtubes in CoD, P90 in CS). These are actually important, because they allow the less skilled player, or in our case, the player with an American or Asian ping, to also be effective and useful in combat. The art is to make sure that these weapons are not so strong that also really good players use them. Meaning they have to be effective, but more skillful weapons should be more effective in the right hands.
I think with this nerf the smines work pretty well in that way. Before, they were so common (and planted so quickly) that for many people the only way to enter a house was prone.
As you can imagine, that is not really how we want the mod to play. Now they are still useful for area denial, but at least can't be spammed everywhere and basically used as a primary weapon. The noobs are finally back in their bottom feeding place
Regarding realism: They are more representative of booby traps than actual mines.