If you are poisoned with a poison with a Potency of 14, then if the poison roll is 1-14, we have an opposed roll, if the poison roll is 15-20, you win (regardless of your CON). It is true that if you have a CON of 15-18, it wouldn't matter in this particular case (but it will matter against poisons with a higher Potency), but if you have a CON below 15 it does matter. If you have a CON of 10 and your roll 11-20, you fail the opposed roll, no matter if the poison roll was 1 or 14.Poison: Your CON-value does not matter, it’s only the poison strength that matters (since poison is active and you are passive if I remeber correctly).
I could do similar examples with any other active/passive skill.
I do know that there are other methods to do this, it makes less of a difference than people thinks, that's all. If we have 12 vs. 15, and they both roll 1-12 then you just compare rolls, if the passive part (15) rolls 16+, he would loose regardless if the active part rolls 1 or 12. If he rolls 13-15 then he wouldn't have any benefit to have 15, in this particular example. Versus someone that has 15 it would be useful of course. 13-15 is only 20% of his successful rolls.
Some people likes to write example with active 5 and passive 15 or something like that and then of course it doesn't matter of you have 6-15, but on the other hand, the active part fails on 6+.
If FL changes this then they must also think about how some rolls work, otherwise we might end up benefit the one with the higher score so much so the one with the lower score can't even succeed.
My personal opinion in this is to bring back the old classic resistance table. Sure it probably has its flaws, but it is classic, but that would probably means a lot of changes to the rules.