It's impossible to say how well Infocom might have done as graphics continued to take focus. The diaspora of Infocom's creative talent worked on many well-beloved graphic adventure games (Moriarty's LOOM and influence on other LucasArts games, Meretsky's The Space Bar and influence as a consultant to a variety of game companies in roughly the same time span, as two examples quickest to mind).

They still probably wouldn't have survived the "adventure game" crash that eventually broke Sierra and LucasArts, but it's interesting to wonder what sort of a contender they might have been had they not been forced to sell to Activision (or had they stumbled into selling to a publisher that was a better fit creatively).

Anyway, its interesting to armchair quarterback with decades of hindsight. The business software was a technical marvel of a sort and potentially had it been much better timed and budgeted it could have eaten Lotus and Excel's lunch. Maybe there's an alternate universe where we are all using an Infocom office suite and Infocom operating system on hardware Z-Machines, which is a fun idea to think about.