Humans were terribly designed to cross the Atlantic by swimming as well, but we designed boats so eventually we did.

Yes, robots are a cheaper and more reliable way to explore and extract resources but I doubt mankind will be happy with just that. We like to explore, and expand, and face challenges so I'd bet that no matter the setbacks or price tag, we will eventually prefer to do this things in person.

As an alternative: we could even redesign ourselves for space exploration if needed be.