@jokerxhisoka He was saying that using the cliche here isn't that bad because people can fall in love for any reason, so why can't characters?
Also the occasional cliche isn't bad, the issue is when everything about a character or story is a cliche. One stray cliche could still be a legitimate character trait or plot point so long as it's not ludicrously unbelievable, which is what Guytsu is arguing is the case here.
This is a world where people put themselves in danger on a daily basis. Someone being saved and falling for the person that saved them is not unbelievable.
It's also entirely possible that this was a subtle jab at the overuse of this trope in other fantasy manga, where the reason for the love interest falling for the MC is almost always because they were saved by the MC.
Before you say "why is it a bad trope in those shows but not here", please note that this manga has a slow building well developed romance from the FMC towards the MC, so using this trope in this situation isn't just the cop out go to cliche the writer chooses to use to introduce a love interest because he can't write a better scenario. It very well could be used just to show exactly what Guytsu was saying: people can fall in love for any reason and it doesn't always make sense.