The American system of economics - what is commonly called "capitalism" - would be best termed "competitivism". The system isn't particularly favorable to owners of capital, nor in the era of the knowledge economy is capital the main feature of production.
Here's a great example. The true capitalists (owners of capital) want to merge two large concerns, AT&T Wireless and T-Mobile. This would allow them to provide more service with less capital, and would reduce competition in mobile phone service and monopolize the market for those with unlocked SIM-card phones. The U.S. government, true to its competitivist values, is suing to block the merger, on the grounds that it would too drastically reduce competition. In a market with only a handful of large firms, the unification of too much capital under one management is detrimental to consumers and workers - even though it is favorable to capitalists.