I suspect at least part of this has to do with the fact that, relative to four wheeled vehicles, you can buy "impressive" motorcycles for relatively little cash compared to say, buying a truly performant sports car. Combine this low cost with an unrelentingly social pressure to show off, mix in one part social media and two parts a belief that you are invincible and I believe you'll have your cocktail of poor outcomes on fast two-wheeled vehicles.

But also, car drivers have this unfortunate tendency "to not see" motorcycles. Technical means like headlight interrupters can improve noticeability but are prohibited in some jurisdictions.