Here in EU, standard fee for SEPA bank transfer is around $0.40 so I would like to see BTC transaction fee lower than that. With Lightening Network it is possible.
However if this would mean that mining is not profitable anymore and common people stop mining and the entire hashing power is in control of few big mining farms in China, then I prefer bigger tx fees because no one wants too centralized hashing power - it would become vulnerable for attacks.