My response to this is complicated (but I'll keep it short):
* I agree with you that anyone who wants to avoid being effectively searched at a border can and there's little the government can ever do about it.
* I think most of the people carrying (say) child pornography into the country aren't too bright to begin with, so maybe that doesn't matter.
* I remember being very upset about the border search exception when I learned about it 10 years ago. It still bugs me.
* If the principal you're disagreeing with is that the state's interests in a secure border outweigh the individual's right to be free from casual, minimally invasive searches, you should know that you're disagreeing with something like 10+ SCOTUS opinions going back to at least the early '70s.
* If the principal you're disagreeing with is that the 4th Amendment allows judges to fill in the blanks on what "reasonable" means, and that "reasonable" overrides "warrant", know that you're disagreeing with something like 175 years of jurisprudence.
* I definitely agree that electronic searches are nonminimal and highly invasive.