I got to this list since I was trying to remember whether the quote from Lang was true or not. Indeed, my copy, first edition I guess, does have that quote on p. 105. I don't know exactly how "positive"(ly) the term "abstract nonsense" is meant in that quote, though. I would imagine that Lang would have been annoyed had someone suggested they do that with any of his books.

Re: Spanier. Yes, the book is terse, and hard to read. I sincerely doubt that the intent was primarily to make a teaching text for beginning grad students; this was, and is, the standard reference book for basic algebraic topology. What makes it hard to read is the fact that every statement is made is as great a generality as he could. This is an advantage for a reference text. I sincerely doubt, however, that there was anything in that book that Spanier could not prove completely.

That being said, I certainly struggled through a course using it. I chose to take algebraic topology from someone else, to avoid taking it from Spanier himself, since I thought he would teach it as generally as was in the book. It turns out, though, that he did back down from that level of abstraction when teaching the course, and perhaps I missed something not taking the course from him.