While I would definitely accept that it isn't heavy at all, glam/hair metal has been part of metal for about four decades, depending on exactly when you count the beginning of glam metal. It's a legitimate branch of the metal tree.

Now, we could do the shitty metalhead thing and debate whether or not that should be the case, but that argument is almost as old as the sub-genre itself, and it's boring as fuck after about two exchanges, so it wouldn't be a long debate.

This song is a classic style hair metal power ballad. Even Ozzy did one of those (with Lita Ford).

There was a post made maybe two or three months ago about the boundaries of metal and hard rock. That boundary can be pretty damn broad, where a given band could be easily classified either direction, like AC/DC. And you'll have bands that bounce back and forth over that boundary from album to album, or even from song to song on the same album.

Glam/hair falls into the same category. It has roots in rock, metal, and yes, pop. Like hard rock, it can range from something like wicked, steel panther or poison to something more like Ratt, or Alice Cooper.

But it is part of the metal tree because of the origins of it. That wicked in particular pushes it more towards a poppy vibe doesn't change that.

Also, as a final note, just dropping a two word declaration like you're an authority is pretty uncool. Remember Wheaton's law.