There's no perfect answer to this particular situation. If you make losing plaintiffs pay, you basically give large companies free license to misuse the intellectual property of small companies. "Loser pays" is proposed in many different contexts (e.g. tort litigation) and has been rejected for the same reasons. In the US, we perceive it to be more fair for defendants to have to deal with litigation costs than to stifle meritorious litigation against deep-pocketed defendants. It's a trade-off.