If'n the rules were unclear, and you don't particularly like the idea, why officially rule it incompatable with FRP instead of clarifying on the side of making the rules parallell. (I'd think nudging the RMC and RMFRP rules slowly closer together would be a positive goal in and of itself.)
Because to us, it isn't unclear at all.
We may not like the ruling we made, but it IS there and this clarification of the rule was made because it was felt that the clarification was needed thanks to there being a difference in opinion in the discussion in which this first topic arose.
In RMFRP, on pages 215 & 219, there are DB breakdowns
specifically for missile fire and for directed spell attacks. The one for missile fire includes parrying, the one for directed spells does not, thus that, along with a few other things, implies no parrying of directed spell attacks in RMFRP.
In RMC, the same is not true. In RMC Spell Law we say shields can effect elemental bolt attacks, and that they are treated and resolved like other physical attacks. The way that the statements are phrased gives you the right to use the Missile Fire Parrying rules against elemental bolt attacks.
And even if we disagree with the ruling that we ourselves made, it is there in the rules, and ICE is NOT in the habit of making rulings to take away something that the rules gives you. If we had realized this BEFORE the RMC books came out, things may have turned out differently.
Quoting the earlier reasoning behind the ruling, the main problem those opposed seem to have is with the italicized statement, i.e. they don't consider bolts a similar attack, or at least not similar enough.
Then a GM can house rule it. That simple.