Totally agree. Setting up a 401(k) seems hard and I'd love help. Picking the right investment fund might also be hard, but placing my savings under the management of a relative stranger feels very uncomfortable.
In a world where Bernie Madoff existed, it'd be almost irresponsible to invest retirement savings with a startup. That being said, WealthFront and Betterment are basically startups, but they seem to be at a different level of maturity.
Of course, I'm not sure how objective my perception is. Would a more credible looking website be all the difference?