A tax loophole is legal. You can hardly fine someone for acting within the law.
Also if they are illegal then they are no longer tax loopholes.
It's kind of like software patching. It can spot gaps, but in so doing may open up others. It has to get increasingly more specific and more rigid, which risks being more confusing and more ineffective.
Sometimes it ends up costing less and generating more income for the public purse to permit certain kinds of tax breaks.
Wouldn't companies just re-locate to tax havens taking the jobs with them?