Ok, let me ask you a question and try to answer it honestly.
Lets assume Chelsea has 3 games in 5 days. First game is against a midtable side winning which guarantees top 4 and almost guarantees 2nd place. Second game is against a good side against whom you don't have any historical rivalry and also are relatively clear of in terms of the 2nd place. Third game is against your biggest historical rival (idk maybe Arsenal?) and your fanbase wants to win that no matter where both teams are in the league or at whatever point in the season. And add to that you have a final coming in a couple of weeks. Now tell me honestly, which game would you want Chelsea to rest players for? Would you honestly want Chelsea to go full strength in the second game, firstly risking your chances in the third game (tiredness, minor injuries, suspension) and secondly risking big injuries to important players for having to play 3 games in 5 days and missing the final, and all just for the sake of the "integrity of fight for the top 4 place" in a season with 38 games?