Well yes, that's obviously true, which is why it's (idealistically speaking) important to verify the routing mechanism.
Of course most of this is mitigated by end-to-end crypto but given that we see all too frequently how fallible that can be, this topic remains of interest. I mean if crypto fails and leaks your private key (a la heartbleed) and it falls into the hands of an attacker who can hijack some BGP routes then that attacker is potentially in a very powerful position. We've seen BGP hijacking by spammers needing clean IPs in the past, so this isn't a totally implausible situation.
Of course most of this is mitigated by end-to-end crypto but given that we see all too frequently how fallible that can be, this topic remains of interest. I mean if crypto fails and leaks your private key (a la heartbleed) and it falls into the hands of an attacker who can hijack some BGP routes then that attacker is potentially in a very powerful position. We've seen BGP hijacking by spammers needing clean IPs in the past, so this isn't a totally implausible situation.