Personally, I'm in favor of the hybrid rules as they currently are. Color identity is ultimately a completely arbitrary additional deckbuilding restriction unique to Commander. The current ruling goes with the simplest implementation - every card has exactly one color identity. Going with the proposed implementation - hybrid cards can have multiple color identities - is an equally valid ruling. Neither is inherently superior to the other, so the main question is which leads to better gameplay.
If we were to change the hybrid ruling....
-decks with fewer colors would have more options available. I do believe that helping out monocolor decks is a valid goal.
-there would be less incentive to run specific color pairings. To some extent, I consider cards like
Privileged Position and
Creakwood Liege to be a payoff or reward for running their color combination.
-some of the more powerful hybrid cards become staples. Maybe every white aggro deck starts running
Dovescape as wrath protection.
-the flavor of color identity is weakened. I believe that this is a bad thing.
-there is more confusion about color identity, making it more likely that people will include invalid cards. I'll point to this very thread as an example of people getting confused.
-the door is opened to similar rulings for twobrid and Phyrexian mana. This is arguably a slippery slope argument... but I see no reason to make a new arbitrary distinction between traditional hybrid mana and other forms of hybrid mana.
-going further down the slipperly slope, this also opens up discussions for cards with alternate casting costs like
Bringer of the Blue Dawn and
Rix Maadi Reveler.
Overall, I believe that the upside of helping out monocolor decks isn't worth the downside of all the additional rules baggage and weakening of color identity.