I would also open this up to garage bands that practice late into the evening hours on a residential street. We have just such a group of individuals across the street and two houses down. I can hear it clearly enough in any part of my house to tell you that the drummer needs a metronome and the singer needs lessons. I completely agree with this and have had the misfortune to live adjacent to such individuals. More than once, I've thought about putting my knowledge of audio properties and hardware to vengeful use in a sort of, "you want noise, I'll show you noise" kind of way.
Unfortunately, I feel like one's expectation of private, quiet space is slowly shrinking as a witch's brew of technological conveniences and bad parenting is making inconsiderate noise polluters more prevalent. If you're seriously asking about the motivation of such individuals, I cannot comment to that. I've never felt the need to "enjoy" any audio at a potentially damaging SPL before and I can't for the life of me understand the allure. At some point, it's a lack of compassion for one's fellow human beings, which unfortunately is becoming more and more pervasive in just about every aspect of life. It's pretty sad.
What is hip?
Gear: Digidesign 003R / Telos Zephyr XStream ISDN codec / JK Audio Broadcast Host digital phone hybrid
PC: HP 6005 Pro MT PC running Windows 7 Pro 64-bit w 3 GHz AMD Phenom II x3 B7, 4GB RAM
DAWs: Sound Forge 10 Pro, Vegas Pro 9, Adobe Audition 3.0, Pro Tools LE 8.04, Reaper x64.