During my one month of playing this game, not once did I have the desire to open any of the loot boxes -- including any seasonal/event ones. How come? It's simple: the loot box system is full of garbage, and has absolutely nothing that's useful or worth paying real money for. Most of the time, they only drop pointless sprays, worthless player emblems, and more junk to take up inventory space. The sole reason why any of that garbage exists is simply to reduce players' chances of getting very rare character skins and play of the game animations -- because those are the only things that are actually worth it.
If you want to pad out your loot box drops with smaller items, fine. But why not at least make those useful or interesting to look at? If sprays were animated, maybe I'd be a little bit happier to get them from a box. Even better, including buffs or boosts (like a double EXP boost) that players could redeem would be nice. SMITE, the popular third-person MOBA from Hi-Rez Studios, includes these sorts of boosts in its chest system -- which you can then use to give your whole team a buff that will grant them more experience, worshipers, and ranking points for the course of a match.
Without anything helpful or useful in them, loot boxes are a waste of time and money.