You forgot the case that the 100 diamonds spender (with money or free diamonds) decide to NOT spend diamonds in this event and save them for the next one.
You are assuming that diamonds spending translate to more progress in league (this is usually correct but not always). In most cases more diamond spend does translate to more point in league. But where you spend it also count with some choices being more effective,
Also for mini-games that require a lot of skill, diamond spending efficiency can vary a lot.
Take the last event on beta (History):
- You can spend diamond to buy extra ticket. But if you cannot collect the generated ticket then a free player with start with more ticket (~60) and the first 12000 diamonds (more or less) will just get a player that spend at the same level of a free player that plays every day. You are spending diamond to compensate not being able to play your ticket every day (you do get better DS selection because you can play in a day with an interesting DS).
- If you are unable to win against the deck selected you might have less progress that someone that selected a deck they CAN beat with available coins. The easy deck is worth 20 GP (I don't remember if there is a league point multiplier). Easy enemy has a total HP of between 31 and 40. If you choose the hard deck beating 35 hp means you are probably dead on the 5th enemy: progress 7! An unskilled player (choosing the wrong deck for coin owned, using cards badly) need to buy 2 extra ticket for every ticket used by the skilled player (I'm not sure if the deck multiplier applies if you loose, game crushed on me every time).
There is another way to get into the 1%: have more players play the event just a little bit. That increase the pool of players and lower the gold threshold by increasing the number of players in gold league. If there are 20000 players, maybe the top 200 are not all diamonds spender like the top 100.
Any system that give prizes to top x will provide an incentive to top spender to spend more so they get more prizes. It's "unfair". But it is the point of the system. And it does pay for the game we free players enjoy.
Hopping for the spenders to stop spending will get you in golden ONCE or twice!
If they stop spending, the for profit company that handle the game (development, server costs, etc.) will just shut down the unprofitable game/server.