Big businesses are able to create massive gains in profits by finding and utilizing loopholes (many of which they work with politicians and lobbyists to create). They would be silly not to look for such things. In doing so, they are able to raise profits (and hopefully create more jobs, income to trickle down to the rest of society).
Tax loopholes. They are a fact of life in the United States. Big businesses are in the business of not only making money but providing employment and income for individuals. While the number of loopholes in our tax code are ridiculous, I cannot fully blame corporations for utilizing them. Instead of being upset with the businesses, our focus should be on the politicians who created those loopholes and making our tax code simpler.
It is human nature to try to increase your profit and make yourself and your works more successful. A big business is run the same way. As such, if by taking advantage of tax loopholes companies can benefit more and make more money, then they will definitely try to look for tax loopholes
Big businesses are driven on the motivation to maximize profit for their investors. It is true that some companies are far more aggressive than others with finding ways to minimize their tax bill. However, I think it's fair to say that all large companies lobby and have some form of presence in government relations to steer legislators their way. It is just that there are some companies that will use every legal maneuver in the book, some will cheat and move operations overseas and then there are some who will want to maintain a better reputation. Having said that, even those who appear to play fair have a few lobbyists in their back pocket.