I think few people in this discussion are worrying about programs directly affecting other programs through memory unsafety, exactly because this doesn't really happen for software that isn't a driver or inside the OS kernel. The problem with memory unsafety is that it often allows exploits that corrupt or steal user data, or gain unauthorized access to a system. That's not a problem when you are the only user of your software and you only have access to your own data, but once you have other peoples data or run on other peoples system I think you should at least consider the advantages of using a safe(r) language.