To be completely honest, comparing the Key drops to the Trials of Gnomus, which are a requirement to earn the new classes, and earning the Unicorn Chomper by hitting Rank 313 in Garden Warfare doesn't equal out.
To earn the Unicorn Chomper you need to hit Rank 313 in Garden Warfare and to earn the Torchwood and Hover Goat 3000 you must complete the Trials of Gnomus so both require you to play towards a purpose, but the similarities begin to diverge from there.
To hit Rank 313 you are able to work at that hour after hour, any day of the week that you choose by doing the Quests for each character class. To earn the Torchwood and Hover Goat you need to do Mystery Portal game modes to earn a Key and those modes are only available from Thursday through Sunday three times a month, with the fourth week given over to a Community Challenge. So immediately you have less time available to work towards the first step of that goal.
To hit Rank 313 you must complete the Quests for each character class and some of those are so sadistically specific and difficult to do on purpose or they are so dependent on the actions of the opponent team that your best bet is to use Skip Challenge Stars which are awarded randomly. you can buy as many Sticker Packs as you wish with the coins that you earn. For the Torchwood and Hover Goat 3000 you have 3 chances to acquire a Key in a month. There is obviously a huge disparity there as one is able to acquire hundreds of Skip Challenge stars during the same period that you have acquiring Keys for the Trials.
Not to be argumentative, but we have many players who post just on these forums who are going into their 6th week without having a full set of Trial Keys, with a few still having no keys at all or only a single one. During that same time period a determined player could hit Rank 313.
The Unicorn Chomper can easily be earned through effort, dedication and the investment of a lot of time whereas you have one 75% chance three times a month to advance one quarter of the way towards the end of the Trials of Gnomus and if the RNG slights you on any one of those chances you're blocked from continuing until the next Mystery Portal reset.
Personally I don't have a problem with the Trials being designed with such a slow pace, I understand why it was done and I can roll with that but at the same time I also understand how incredibly frustrating it must be for those players who have participated in the 4 Mystery Portal each week over the last 5 weeks and who are still empty handed or who have only one Key.
From a purely "Public Relations" standpoint it's a bad move to have players, who you want to enjoy your game, continue playing it and to purchase any sequels that you may continue to produce, be facing the prospect of being repeatedly frustrated over and over by a RNG system which apparently has already skewed away from the odds (75 % being 3 Keys after 4 opportunities) for certain players (0 Keys after 4 opportunities or 1 Key after 4 opportunities).
I'm not suggesting that it be made easy to acquire the characters, like by selling them or putting them into Sticker Packs or letting people skip over the Trials they they can't finish as suggested elsewhere, but in all fairness they should consider putting a light at the end of the proverbial tunnel by setting a hard cap as to how long someone can be expected to be forced to wait for their Keys.
