You also have to think about who the audience was (Unix users) and what they were used to (Gopher, irc, plaintext email). With all of those technologies they were used to being in control of the styling of what they consumed. One person's styles for irc could be completely different than another's, and that was fine. The idea that things should be published with one rigid style which must be used to consume it was foreign and not all that attractive.
You could make a case that the only reason any of this happened when it did was because the browsers were reducing the amount of control the end users had on the page styling. If Mosaic had been super configurable in it's styling, it's possible it would have taken even longer for CSS to come about.