Care to explain why?
Trying to claim that windows still somehow would have something to do with CP/M. Or that Linux or BSD would have something to do with AT&T line printer manager. Totally absurd and ridiculous claims, you can only laugh at those.
Grouping AmigaOS with Haiku is IMO rather stupid as well.
Why would any developer target some very small and obscure system such as Haiku, or even obscurer such as AmigaOS? Just because you think those OSes are better or have better APIs (they don't, at least not AmigaOS)? There are after all such concepts as "market share" and "potential user base"...
If Firefox managed to make a dent to Internet Explorer, in a market were it controlled 90+% of the market and everything was built for it, then why not something couldn't possibly overtake Windows?
Are you for real?