I could be stirring the pot somewhat, but calling something a major upgrade simply because the version has incremented by one doesn't necessarily mean it's actually a major upgrade.
I'm kind of with the OP in this respect viz-a-viz what we're paying for (which I do for bugfixes more than anything else at this point) and what we're actually getting.
I really have to take issue with people that come to this conclusion.. Lord knows I've had my beefs with Jim over feature support, etc but the fact of the matter is, JRiver offers one of the best software upgrade/pricing models on the planet.
I've been purchasing upgrades since around MC 17, and have never felt the cost was unjustified. It's disingenuous to argue that major version increments are simple upgrades. Pretty much every version of JRiver that goes through a full versioning increase comes with new features, as well as roadmapped features for the rest of the year following the release. The bulk of these features are often user requests for new things or refinements of existing functionality. And in addition to that you get periodic updates with bugfixes and stability.
This isn't like Firefox and Chrome where they pump up the major revision number in a race to the bottom for very few, if any, actual improvements. You're paying for well tested, professionally developed software by people who are actually passionate about their product, not some big box corporate with an army of lifeless coders slaving away to implement a spreadsheet of marketing research.
JRiver also offers deep discounts on upgrading every year, sometimes more than once, and almost always they extend the sale period so as many people as possible can upgrade at a lower price.
The part that makes all the above "worth it", is the fact that this is perpetually licensed software. As had been pointed out, you can buy a major version and use it forever, in some cases important bugfixes or under the hood changes will even get backported to the previous years version at no additional cost.
You buy it, you own it. It doesn't stop working because you stop paying. I usually upgrade yearly because I support this philosophy. I grew up in the age of software where you bought it and you owned it. I understand what we are losing to all these "software as a service" models of subscription.
For everything JRiver Media Center is capable of, I think it is a very fair price, especially if you go in for a Master license.
If the features being added are of no use to you, then skip upgrades at your leisure. Just remember you can always take advantage of upgrade discount sales even when you come from a much older version of the software - that alone is also unique among a lot of software companies.