Because, I have been doing this sort of thing for a really long time and this community is in no real position to make any kind of demand that Interplay change anything.
I am not a lawyer, and none of this should be construed to be legal advice, but my layman's grasp of these things based on 15 years of dealing with lawyers and contracts and entertainment software leads me to believe the following:
1) Its free press for Inferno, and by extension HLP and the rest of us.
2) Chances are good that they have an implied (if not explicit) legal right to any derivative art (anything that re-uses textures, etc)
3) While HLP doesn't condone it directly, the lions share of this community believes they can do whatever they want with FS2 binaries, a questionable at best legal position
The Inferno authors could email them and thank them for the spotlight, the SCP could email them similarly, but nobody should email them and tell them to change the art. That's an expressway to a cease and desist or worse.
We should be supporting them in their return or ignoring it.
That's why I believe your suggestion is fundamentally stupid.