I try to avoid climbing the busier mountain roads, but cyclists have every right to enjoy epic canyon/mountain rides just as you do. Don't drive dangerously around blind corners (you shouldn't do this anyway lest you want to risk crashing into a lane crosser,) and you won't come close to hitting a cyclist. Give them a wide berth and gun it when the opposite lane is clear. Don't honk at them, don't pass within 3 feet, just cross the lane unless it's a double yellow.
I do descend the busier roads. When they have a -5% grade or better I can hit 50+ mph unless there is a headwind or crosswind.
For example HWY 84 east of Skyline here in the Bay Area? A dozen cyclists might climb that a day whereas 100 cyclists might descend it. 70-90 cyclists ascend Old La Honda every day, which is right next to it. Most cyclists taking to these roads are quite experienced, and not stupid. I'd also wager a higher percentage of weekend drivers drive beyond their skill/practice level than these riders. Shit, just look at this channel:
RNickeyMouse
Specifically this video:
Just saying, generally calling out cyclists who aren't breaking laws gets old, especially when they are very few and far between compared to cars.
Another example from that channel:
Are the cyclists really to blame? What if that was a broken down car or one of the many pro photographers that line "The Snake?" No, the person who crashed into them was at fault and no one else. Cyclists also get hit on quiet suburban streets or in supposedly bike friendly facilities like Golden Gate Park.