I don't really understand why people complain about quest item drop rates in particular? You could complain about overall reward value, if you think it's worthless trying to obtain. You say "10% is too much, because I got extra quest items". But reaction to this from devs can be the following: "ok, they don't want too many quest items, so next time we will give them 50 free chests instead of 100 free chests".
If your main point is that you have extra quest items that stuck in your inventory, solution is easy - just sell extras (on market or in the shop directly for 50$ per unit). The idea of the event is that you can get something to warm your soul FOR FREE. Free is always good, don't understand what you are complaining about specifically. And as Dr.Roth said already you're not only getting "useless" items but also some useful items as well - it's the positive side of event, so keep focusing on positive things and life will be easier
In the end, nobody forces players to spam 15s jobs to get snowflakes. Because of high drop rates there will be plenty of extras on the market for you if you just want to finish questlines without farming snowflakes. I sold my extras on the market and I've checked who bought them - all items sold to players who have level higher than 160. I think those players made their choice easily - don't farm if you don't like the outcome of farming.
mic dropped, sorry.