I can think of a few explanations for a hard/soft distinction among intellectual properties. First, patents often cover physical devices, so they often have a physical tangibility, while copyrights, trademarks and other IPs may be more intangible by comparison (even though patents protect “ideas,” which is as intangible as they come). Second, the hard/soft distinction might imply some difference in the degree of the practice’s difficulty, i.e., the perception that patent law, and any associated technology, are complicated and “hard,” while other IPs are relatively easy and “soft” by comparison.