Meaningless to some, but prior business experience in the private sector and proven executive management skill are something I put at the top of my long list of desirable attributes in a candidate for President of the U.S. Afterall, the President is the CEO of the largest organization on the planet. Prior experience as a Chief Executive in a large organization is the primary reason that Governors are elected President much more often than members of the House and Senate.
Mitt Romney's highly successful career in business is only one aspect of his leadership ability and résumé to examine that he developed further in public office (see my tagline). In comparison, Ross Perot was a one-dimensional candidate running on reducing the federal budget deficit, never elected to public office, and a bit of an eccentric to put it very kindly.
Why? The last person who could really run on this was Herbert Hoover and it's not like Romney can bring that up.