>>45506574Kind of like
>>45506612 said. The means more than the end are what people mainly find fault with. People can generally take a loss if it's handled properly. The writers did several things to lead viewers to believe Ash was going to win. These include, but are not limited to:
The japanese title of this episode is "Kalos League Victory! Ash's Ultimate Match!!"
The powered up orange water shuriken served no purpose and was shown in preview material for the purpose of false expectations, which were reinforced when it wasn't used in the prior battle against Sawyer.
Charizard was showing signs of struggling such as falling to one knee against Pikachu's Thunderbolt, but it still takes all of Greninja's attacks and looks in better shape coming out of the fight with Greninja than it did going in.
Besides independent gauges of strength like Ash getting the upper hand against Diantha, Ash and Alain had fought two times before the Kalos League. The first time was before the bigger water shuriken was formed, which Alain won. The second time, Greninja was better with the ash greninja thing and was doing better against Charizard until Ash passed out like he did against Diantha. There was a clear buildup to Ash surpassing Alain that the writers decided not to follow through on, even though the two prior losses' cause, Greninja not mastering its new form and Ash passing out, were not present for round 3.
Type disadvantages, though this one has less merit given the anime's history and how Ash beat Sawyer's Sceptile at a type disadvantage in the prior battle.