Earlier quoted context omitted.
If you have "no presence at all" then you either have no money, in which case you can't really afford entering it (in this case, anyway), or you have the money, but then the above rules still apply. Effectively it would be better to market your mediocre product to physicians than to kill the cash-cow. Also, large risks are actually typical for this type of research. It's expensive and risky, so it has to give really…
Google had no presence at all in the spreadsheet market in 2005. I guess they really couldn't afford to enter the spreadsheet market. Too bad, because if google had money, and the above rules didn't apply, then google might create a free spreadsheet web service that competes with MS Excel even at the risk of destroying a gigantic cash cow owned by somebody else.
As an analogy Google Docs falls safely on the treatment side of the fence.