That's a corruption of government, and isn't endemic to corporations. If the government had fewer favors to dole out which mostly is in granting government contracts for socialized services, "stimulus" (ie, subsidies), or providing exceptions to regulations, there'd be less of a need to grease the wheels of government (either via direct graft, or indirect campaign contributions).

Big government has big contracts that need big companies to deliver and manage them; solution, smaller government. (Corporate) welfare government wants to make sure everyone gets a fair chance (via stimulus), including enterprises that productive capital markets find too risky; solution, smaller governmental budgets. Utopian governments believe that society and the world can be engineered to a certain "perfection" (insert megalomaniacal vision here) if just enough constraints (ie, regulations) are placed upon it, like choke collars; solution, fewer constraints.

Big corporations provide the anonimity and scale to meet the needs of large contracts, be non-personal recipients of stimulus (as "job creators"), and have enough contentrated power to scale or bypass the regulatory walls. Small organizations and individuals cannot meet any of these needs effectively.

The solution is to get rid of big government. :-)