Because entire point of their work is to find the issues as fast as possible, and most importantly, before others.
You have a lot more faith than I do that companies paying security researchers will not try to cut corners by directing the researchers they employ or hire to look at stuff that they aren't even about to install.
You have a lot more faith than I do that companies paying security researchers will not try to cut corners by directing the researchers they employ or hire to look at stuff that they aren't even about to install.