You could endlessly send coins to yourself sure, but fees would eat up your funds, its based on addresses in the previous block converted to a hex format, a snippet of that address then used to search the previous block hash for matches, if there is a match the address receives part of the mining subsidy.  Its not very easy to have a match.  Because of this, there is additional checking the verifies the coinbase transactions including address, value, size etc further securing the blockchain and eliminating the possibility of disabling the functionality.