If you're a researcher it isn't a big deal because you're not concerned with making money. If you're a publically traded business, it is a big deal because every year that goes away, is a year of exclusive rights to use the patent.
Check out Orbital Sciences Corp.'s patents on air-launched rockets. The patents are starting to expire on the rights which they've had from the 90s. Soon Orbital wont be the sole competitor in that niche. They've since branched their business into other markets (small sat and rocket manufacturing).