The claim here is that the shadow exists whether you want to acknowledge it or not. Failure to integrate it is actually irresponsible.
1) you fail to recognize it in others, opening yourself to be manipulated and hurt by others, or stand by as someone else is hurt/manipulated.
2) you fail to recognize it within yourself, meaning any moment of weakness it can take over you and you'd hurt another, including those you care about.
Its not fun work, but it should be practiced in some capacity. If anything you can find guidance (literally - through those you know, or figuratively from the characters or personas you can't immediately converse with - stories, lecturers etc.) Regardless, you can do it if you think its a path you should take π«π