network users at that time already had software for ftp and other common tools. Gopher sort of linked logically to an ftp idea. Mosaic was often introduced in the same sentence as "uses a format called HTML" .. Mosaic seemed interesting but also it was obvious that pages in that format would have to become popular, to make more of them. There wasn't a big reason to switch your daily software to Mosaic since stable apps were better for their existing uses. It was a very rare thing to have access to a NeXT machine (maybe not on YNews).

From my point of view it was Netscape that made a big splash, a year+ later, with a lot of publicity and good graphic design. Mosaic itself was an awkward demo with an interesting nerdy story.