I think Ray Kurzweil would agree with you. That's why he uses language like "the intuitive linear view" and "the historical exponential view" 
The whole POINT is that the predictions sound crazy. But the reason why he gathers such a following is because, unlike most "futurists", who make bold predictions for decades in the future only to slink away and hide when the time comes to for a test, Kurzweil welcomes rigorous evaluation of his past predictions. 
You can read through second link there and decide for yourself. He laboriously goes point for point and evaluates (in 2010) how he did in his earlier predictions from decades before. I gotta say, it's pretty impressive.
So the reason people listen to him is because his future predictions are even MORE crazy, but it's hard to argue with an 87% accuracy rate. Even his failures aren't WAY off the mark.
1 - http://www.kurzweilai.net/the-law-of-accelerating-returns
2 - http://www.kurzweilai.net/predictions.php
Some of those predictions were a year or two late, in 2010 or 2011, but does a couple of years really matter in the grand scheme of things?
Predicting that self-driving cars would occur in ten years in the late 90s is pretty extraordinary, especially if you go to youtube and load up a commercial for Windows 98 and get a flashback of how primitive the tech environment actually was back then.
Kurzweil seems to always get technological capabilities right. Where he sometimes falls flat is in technological adoption - how actual consumers are willing to interact with technology, especially where bureaucracies are involved- see his predictions on the adoption of elearning in the classroom, or using speech recognition as an interface in an office environment.