Why should eating two salads with vinaigrette be potentially dangerous to your health?
Personally, I quite like the vinaigrette. IMO AC has two choices:
1) replace it with another dressing - not sure there are any better alternatives out there that appeal to most pax
2) offer a choice of dressings - I think a light yoghurt / herb dressing could work well (have never been a fan of the heavy thousand island or caesar cream dressings served on some US airlines).
If the "petition" is for #2, sure, though personally I think there are more important issues.
On a related note, I have noticed a slight improvement in the bread quality on some flights, but I'd still like to see a larger variety of breads on int'l flights. How about some garlic bread or maybe some focaccia bread?