Everybody complains (in my opinion, and by ‘everybody’, I suppose I mean the vocal minority we see on the forums), because the event takes a week. They forget that the first day takes 1 second, days 2, 4, and 6 might take ten minutes each (and that is if you take the time to look in-depth at your your opponent and haven’t saved your most common defensive and offensive squad set ups).
The battle days of 3, 5, and 7 might take a little bit longer (but not very much, it’s usually just a matter of who guessed the right hard counters to keep for offense), but those battles usually go fairly fast, because instead of grueling mirror matches, it is mostly rock/paper/scissors.
So all told, while it takes a week to get, you really aren’t playing for much more than, (if even) an hour. I think the top end rewards are fine for that. And if you aren’t earning those yet (I haven’t - usually 2 and 1, and I went 1 and 2 in the last one), that should be your incentive to refine your inventory and work towards it.