It's not obvious that the losing party should have to pay the legal fees. (By that, I take it you mean lawyer's cost, not court costs.) To a measurable extent, success is based on ability to pay. If an individual is sued by someone with corporate counsel or a relatively poor person is sued by an incredibly rich person, should they be made to pay twice?

It also would invite too many disputes into the courts, since an aggrieved party could feel it's almost free - the person who hurts them to the tune of a couple of hundred dollars will have to pay tens of thousands and they get nothing. It is possible that some disputes have a genuine good party and a genuine dodgy party, but in many cases they're just people who life happened to. The loser should compensate the other party but not necessarily get punished. If the loser was being malicious, they should be made to pay. But we shouldn't assume the loser is malicious, just that they lost.

It seems to me if you want the loser to pay, you'd have to create a regulated system for costs in order for them to be fair. A clever lawyer might have a way to take additional payments, but they'd have to be outside of the system, not recoverable by the court. But doesn't that end up in exactly the same situation as before?