I've thought for a long time why I absolutely agree with this sentiment and the best I can come up with is that the Internet Archive feels to me like the embodiment of the old internet, not this marketing driven, data steal-and-sell, VC backed cyberpunk dystopia Internet that we have everywhere else.
It's the same sort of feeling as I why I enjoy this site, wikipedia, and so on. Bonus, IA is also a bit of an organizational mess, but rewards the adventurer with rich treasure.
(I was recently on a Korean history kick and came across not only 1, but several entirely different first hand books written by visitors in the late 19th and early 20th century, scanned in, freely accessible/downloadable, in a variety of formats, and with an excellent on-web reader. These books are so out of print I checked with three local counties for copies and none of them even have references to any of them in their catalog -- treasure!)