In a 2 player game, there is really no need to visit Mt. Olympus to obtain the first player token. If you are not currently the first player, you will automatically become first player at the end of the current round anyway.
In a 2 player game, there are 3 tokens each for a total of 6 and 8 slots available on the board. The players do not necessarily want to visit the Temple, so the token doesn't necessarily change hands.
Now, maybe the rules need to clarify that for a 2 player game. I can hear the argument that if you're already first player and you visit Mt. Olympus then you will not need to sacrifice the first player token at the end of the round. ?????
If you are the 1st player and you always have 4 quests available at the beginning of each turn, how will you place your secret quest cards? As per the rulebook, "These cards may be placed on the Quest track at any point during that player's round, provided there is an empty Quest space.
That is, the 1st player token could be a trap.
Of course, you still get the benefit of gaining another DI card regardless of the first player token decision.
You also "lock" the 1st player token for you next turn, if you so need a fresh 4 new cards, or that legendary one no one managed yet