But in terms of the actual material, the description pretty much fits- guess "glam metal" is a substitute term and the dramatic, theatrical yet relatively poppy/accessible nature of JP's music seems to align with hair/glam metal more than their fans would probably care to admit. And as Billdude points out, the same can be said about Van Halen (though because they started in the 80's, I guess that's maybe a less controversial opinion despite all the Eddie fan worship?).
Also, I guess hair/glam metal bands were mostly American so the fact that JP was English is another reason for their fans' refusal to acknowledge the connection (also maybe part of why they remind me of Queen)? But whatever- like I mentioned to Trung recently, musical subgenres are typically pretty useless/arbitrary anyway and my main point was that while I'll never be a JP fan, I can objectively admit that they're better than most of their contemporaries in every way.