Forcing out profit means there is less money for reinvesting. This would mean your network would fall behind in the quality it provides, until the profit enterprises are a better deal, even after their profit is extracted.
You could go against that by having the intention of turning a profit but committing to reinvesting, but that is still extracting that profit. Moreover, it encourages the same exploitative behavior.
In general, profit isn't bad. Trades are only made when both parties are better of afterwards, so in principle, more trade means everyone is better off. The devil lies in the balance between how much better off both parties are.
OK, so then include a percentage of price for reinvestment and eliminate all other profit? Or put all of this profit into a socialised pool? Also for-profit competitors would be effectively shut out of the network by agreement. The vision would be vertical integration with minimal profit at each step, thus opportunities for concentration of wealth are minimised. Interestingly this seems to be happening to a degree with Amazon, where profits are arbitraged out of the system (though to varying degrees between participants).
You could go against that by having the intention of turning a profit but committing to reinvesting, but that is still extracting that profit. Moreover, it encourages the same exploitative behavior.
In general, profit isn't bad. Trades are only made when both parties are better of afterwards, so in principle, more trade means everyone is better off. The devil lies in the balance between how much better off both parties are.