Do business unless proven harmful?

Recently, there was a proposal for foreign direct investment (FDI) in retail sector and for various reasons, it did not happen.
Some opined in support of this proposal that, one should not be prevented without a good reason in setting up a business unless it is proven that it causes more harm than good for economy.
This not an acceptable opinion. Though competition is good for the economy, brings the best out, worldwide, there are various forms of protection provided to local businesses and direct/indirect subsidies to help them. May be in some countries, FDI in retail proved beneficial to the farmers and direct producers by eliminating the intermediaries. But, it varies from region to region.
If FDI in retail is allowed and caused harm to the economy, can we remove FDI and reverse it. At that time, same people may opine that it is a retrograde step and reversal of reforms. By the time we realized the harm, many retail shops and small players would have closed due to losses leading to creation of monopoly or formation of syndicates.
Generally, to gain market share, new entrants offer their services at much lesser prices, sometimes even below the cost of the product. At the same time, the cost of the same product offered by the same company in some other city may be higher. When small business houses unable to bear the onslaught of big houses close the shop, these big companies increase the prices of their products and people will be left with little or no choise but to pay the price.
What happened in telecom, airline and other sectors is known to everybody. Though, public got benefited due to tariff wars between the companies in the industry, the industry as a whole is bleeding and the lenders are terming the loans and investment in these companies as non-performing asset. In an extreme situation, those who took loan will file bankruptcy. Again, recently few companies in telecom sector increased their tariff to reduce losses. But, finally, it is the the common man, who has to bear the loss in the form of lost investment for their betterment. There is no difference between such companies and conmen. One cheats in the name of business and the other cheats the individuals directly.

As safety professionals, all of us are against any activity till the hazards are identified and eliminated/ controlled. If we wait for harm to happen, I am sure there will be many Bhopal like accidents in any business. Though the harmful effects of Bhopal accident is limited to town, Chernobyl accident is limited to few villages, atomic bomb explosion is limited to Hiroshima and Nagasaki, playing with economy can lead to kneeling down of entire nation.
http://www.hindustantimes.com/India-news/NewDelhi/What-s-FDI-in-retail/Article1-775543.aspx
http://articles.timesofindia.indiatimes.com/2011-11-29/india/30453728_1_retail-sector-small-retailers-global-retail-giants
http://www.rediff.com/business/slide-show/slide-show-1-fdi-in-retail-kiranas-unfazed-ask-what-the-fuss-is-all-about/20111206.htm