Well, if you personally were building von Neumann machines do any purpose in the solar system, would YOU be interested in sending some to neighboring systems knowing that you could conceivably get a response in your lifetime.

Would you be at all interested in expanding that project to outlast you?

And even if you personally wouldn’t be so inclined, surely you know or have met people who might?

Once you have the self replication, expanding scope may just be additional code…