Force? No it doesn't.
"Section 40 forces all news media publications to pay for the lawyers of both sides in any court case" - No, it doesn't.
Section 40 encourages news organisations to join a complaints arbitration scheme.
If El Reg chooses not to do that, then THE REG is forcing complainants to pay for expensive legal services when a cheaper arbitration service is available. Therefore it is fair that El Reg should foot the bill for making that choice.
Not all complainants are going to be millionaires. Section 40 is designed to protect ordinary Joes.