Having no issues with it doesn't equate to it being good or workable, or right. It just mean you don't dislike it.
It's a quite backwards system that fails to convey anything that is found in reality, in favor of fairy-tale morality or values. People only start having issues with those when they start trying to figuring out the alignment of people that are less clear cut, that may act for the greater good but do it via "evil" actions. It's fine if you're always going to play the goody-two-shoes mighty hero trying to defeat the evil forces of darkness and undead and demons and devils and hell and other things with horns and bad breath (or, even introduce a "twist" and play the evil side). Otherwise, everybody's Neutral and there's no point to any of it.
It's also unnecessary, used to keep score of who's "roleplaying right", because killing the innocent Dominated blacksmith in self defense was an evil... wait, no, good action. Or... it wasn't evil, but it was not-good. Or something silly like that. Or it gets ignored completely until someone has to cast Circle of Protection, in which case it's the DM's job to keep track of all the actions to determine if the PCs get alignment shifts, which won't get roleplayed anyway.
And IF it gets roleplayed, it means trying to figure out if something's Good-approved before doing it instead of trying to figure out "how would my hero react to X" or try to do something heroic. Then it turns out Heroic is good, so that bloodthirsty Orc Warmonger that jumped across the lava chasm to save his loved ones just got too many shifts towards Good and now suddenly his Anti-Paladin minions get the urge to eviscerate him.
In the end, it's just an excuse to go attack the Evil mastermind just because he's probably up to no Good, and slaughter whole tribes of goblins without having to think too much about it.