To tell you the truth, I had never heard of Erwise until today. A have a few questions about Erwise:
- Did it support graphics other that XBM?
- Did it render HTML, or some other markup language?
I did some consulting for a company called HyperMedia Corporation in 1991-92. As part of that work, I watched closely the development of HTML, NCSA Mosaic, and the lot. HMC's markup language was proprietary and binary. The first thing that struck me about HTML was the ease of editing--you didn't need a dedicated editor. Then, I remember seeing early builds of NCSA's browser (to become Mosaic) when they first added, IIRC, gif support. I remember being absolutely floored with the ability to create attractive content in only a few minutes. My first thought after seeing it was, "I need to find a new job!" Sure enough, within a few months HMC was out of business.
The end result is that there were many factors that led to the success of NCSA Mosaic and Netscape. First, Mosaic ran on platforms other than the X Window System, so it was more accessible. Second, it was among the first to support usable graphics (i.e. not XBM), at least on an accessible platform (Emacs' browser & WorldWideWeb.app had early image support, too, but both were on platforms that had very narrow distribution possibilities). Third, it used standard HTML.
Erwise might have had all of these, with the one caveat that it supported only Unix/X Window System. Hard to say from this article. However, I think it's a little simplistic to say that funding was the only thing holding these guys back from Netscape-like success.