It's so weird seeing people pleased to see Charles Xavier back saying his immortal line.
In the comics, just as Magneto has been on the side of the angels for the last twenty plus years, ol' chuck X has been a moderately unrepentant asshole, soundly shunned by his one-time "Son", Scott Summers and even given lessons in morality by Emma Frost, the White Queen! And lately he figured he could save Mutantkind from eternal dominion by shooting child Moira McTaggert in her past. He was prevented from doing so (thank you, Rachel Summers) but only after he pulled the trigger.
The Onslaught storyline in the early 90s was among the first to really take the shine off his character, Onslaught's revelations re: Xavier's secret 'love' of his underage student, Jean Grey, serving to shatter trust and cast him in a much darker light. Subsequent stories, such as revelations he knew all along Scott had another brother, simply pushed him further away from his original portrayal os a moral guiding light for the X-Men, undoubtedly leading to their wholesale departure from him in the Utopia era, Cyclops' ascendance as the mutant driving force ("Cyclops Was Right") and Magneto's welcome into the fold as a more or less permanent state of affairs. There was a fair amount of revisitiation of earlier decisions too; looking at how he talks a very noble game but in practice he oversteps moral boundaries almost as a matter of course, wiping the minds of entire towns to protect the X-Men's identities, leaving people to believe him dead (as he just did in the cartoon...!) and more besides.
He's also a fairly crappy father to his son, David a.k.a Legion. I have one of those so it's less easy to forgive him that. Even in the Krakoan era (Krakoa is for ALL Mutants) where the likes of Apocalypse and Mr Sinister were made members of the governing council, he mistook David's peaceful reconciliatory overtures as David seeking revenge, and -get this- struck back first. Even when he's Winning at Life he's still a jerk (Thank you for that immortal insult, Kitty Pride).
And going purely by the cartoon let's not gloss over his arrogant presumption in calling for "his" X-Men when his Will handed them wholesale to Magneto, and he's subjected them all to the pain and grief of his loss for MONTHS.