Randomness is annoying, but as Malfiore was saying, RNG is apart of every game everywhere, even more so in F2P games. Kill a boss, one player gets [super rare item] on first kill, another player doesn't have it after 100 kills. It's simply a part of games and it's okay for some players to have more "stuff" than others.
That being said, here is how I would have designed the event:
1) Get rid of the daily buildings and the chests. Instead, make the event into a sort of store. Every daily building is listed in the store for a certain price of moon shards. You can buy whichever building you want, once you have enough moon shards, but limit the number of each building that you can own, probably 1 for the best ones and 5 for the 1x1 buildings.
2) Unlimited quests available ranging in difficulty with the most difficult giving the most moon shards. You can skip the quests, but probably need to complete the hardest ones to afford the best buildings. Higher tier players have an easier time completing the hardest quests.
3) Use your moon shards to buy the building of your choice and every moon shard spent turns into a sun shard which goes toward unlocking best buildings. The grand prize probably requires you to unlock every single other building, or at least very close.
4) To keep some random fun in the event, every building you unlock gives you a chest to open. Inside the chest are the current random rewards (minus daily buildings) but in addition, they add a few VERY nice but VERY rare building prizes that you have a slim chance of receiving.
5) For those that don't have time or desire to diligently work on quests, they can buy moon shards at reasonable price so that the total cost of buildings like the Glossy Garden is similar to other bought buildings. I probably wouldn't allow the grand prize to be bought outright but if someone had the desire and money, they could buy all the other buildings to unlock the grand prize. You could also probably buy various packs of chests for those that wanted to play the lottery for the super rare buildings. Maybe even allow you to use moon shards to buy chests if you didn't care about the other buildings available or if you had completed the grand prize already.
The way I see it, this event would reward the players who have worked hard to get to a higher tier (not me) as well as those who were willing to login diligently. It would also reward those with excess cash laying around (also not me) as it should in any F2P game. My favorite F2P games are ones where it is possible to achieve the same thing with paying or not paying as long as you put in the effort. Paying should always be the lazy way out....not always faster, but some cases are okay. At the same time, EVERYONE could get every prize, some easier than others, and the rewards would be equal across all tiers. A brand new player starting out may be able to work super hard all event and just barely earn the Glossy Garden but nothing else. Sure it is a HUGE boost for them, but good for them for earning it. Some one else may earn every building with 5 days to go and just blow shards on chests. The random chests would still add fun and occasionally the fellowship could rejoice together as 1 person got the rare building and Inno would still get their money as people played the lottery or were lazy.
Just my thoughts.