Not sure what you guys have been using as your source for new music, but there is absolutely no lack of heavy, hard-hitting straight-up rock music being made today. I'm an old guy too, but some of my favorite bands are making killer rock music right now (and within the last few years). I mean, we all have an affinity for the music we grew up with and tend to compare everything else to it but damn there is some killer hard/heavy rock being made by the kids today. Mainstream? Hell no, but it's out there if you go looking.
Edit: Got me thinking, just relatively recent hard/heavy bands (records out in the last few years) worth checking out kind of off the top of my playlist, and not intended to be a complete/comprehensive list:
Fireball Ministry
Sasquatch
Dozer
Fu Manchu
Rival Sons
Orange Goblin
Glowsun
Isaak
Gozu
Royal Blood
House of Broken Promises
The Sword
Mastodon
Clutch
Wo Fat
Greenleaf
The Company Band
Red Giant
Unida
Karma to Burn
Queens Of The Stoneage
Freedom Hawk
Earthless
Svolk
Mothership
Electric Wizard
Mos Generator
Mammoth Mammoth
Red Stone Souls
Astroqueen
Ponomero Sundown
Spirit Caravan
Lonely Kamel
Truckfighters
The Shrine
Slo Burn
Seemless
Fiftywatthead
Robot Lords of Tokyo
Clouds