Any book with a new way of thinking or a new theory will get a lot of bad reviews. The things to focus on in his book are not the small artifacts, but the monumental constructions that seem completely impossible even by todays standards. The time frame for the pyramids is 20 years. That means a multi ton brick was excavated, carved, transported and laid every 9 seconds. We could not build the pyramids today with our technology to that absolute perfection in 20 years. What about all the carvings in Egyptian tombs? How did they carve those in pitch black darkness? We know that fires cannot be lit inside of these tombs because of the lack of oxygen, try and light a lighter in there it wont light, you need electricity.
Nazca lines can only be seen by an aircraft; Why would someone create such glyph that they cannot even see. Other Nazca lines are laid much like an airport on top of mountains, these mountains have no summit they are completely flat, yet all surrounding mountains have their summits. There is also no material from the missing summits to be found anywhere. What purpose can these lines actually serve? Where is the missing material. What about Puma Punka in Tiahuanaco? Certain of these andesite blocks resembles a machinist's work, with straight, true edges and countersunk geometrical shapes. Some of the sandstone and andesite blocks are over 27 feet long. The nearest source for this material is 20 km to the north from the site. Now I'm not saying that's completely impossible for a man to create with limited technology, but the elevation of this structure is so high that the plants that grow there are completely stunted, and oxygen levels are way too low for anyone to labor in. Building something that complex at that elevation needs technology not man power.
Many people discredit Von Daniken as a fraud, but if you actually read his book he never says "this is", "this happened this way" or "this is a fact". He merely asks "why?" and "how?", everyone completely passes over his question marks and takes them as statements. No scholar has yet to come up with any rational reason or method of these megaliths, all they say to these theories is "wheres the space ship?". Do you think if ancient astronauts came here they would just leave one of their ships behind? No! So all we have to work with is what is here and what we can see and touch, and what we come up with is speculation, not proven facts yet. Our scholars can only speculate about why these structures are there and how they built them, there is no proof of why or how they are there, but we take what our scholars say as fact because "they know it all".