Logic Pro X is not an "upgrade", it is a whole new app re-written from the ground up. It is cheaper than "upgrades" used to cost with legacy Logic Pro. All upgrades for LPX have and will be free. Logic 9 was discontinued YEARS go.
The operating system has evolved, uses newer technology, and older 32 bit apps simply won't run on it today. All operating systems have this same evolutionary process. It is not unique to Apple.
Logic Pro X is far superior to the legacy app. It is very worth the upgrade. And if you can't afford the price after all these YEARS of Logic 9 being discontinued, well, I have no idea what to tell you.
If you own a Ford Model T, the Ford motor company today can't help you fix anything. Does that make them a dishonest company?