It doesn't make any sense to have the ground station transmit to figure out its location. To give a baseline, that's how the original analogue COSPAS SARSAT worked last century, using doppler measurements to get a location over time - and its accuracy was appalling, a human operator has to use equipment to narrow down where the signal is, it takes significant time to get a 1 nautical mile search area. Which is much better than "I dunno, in the sea?" for a lost ship or plane, but you're still going to need a serious search-and-rescue operation to find anybody.
A modern digital COSPAS SARSAT system you may have seen if you're a serious hiker or outback flyer just does GPS, it uses GPS to figure out where it is, then sends a digital signal that says "I need help, here are my GPS co-ordinates" hence the slogan "Taking the search out of search and rescue".
The current Breitling Emergency (a bulky men's watch, but it wouldn't look out of place on some big out-of-doors type guy's wrist) is a working PLB transmitter.
So that means signals from it can be received not just 21000km up, but 36000km up where Geostationary birds live.
If you activate it, that watch will transmit the digital signal with its unique ID in it, and assuming you filled all the paperwork out soon after somebody from the relevant local emergency response (maybe a coastguard, mountain rescue, that sort of thing) will be phoning your emergency contacts
"Hi, do you know nraynaud? They went flying today? OK, do you know where they were headed? We have an emergency transmission from their beacon so we're going to send somebody to take a look and check they're OK. We'll let you know, thanks".
A "real" beacon would be better, more robust, better battery life, easier and more obvious for random strangers to operate if you're unconscious, not to mention much cheaper. But the Emergency has the advantage that you'll actually have it when shit goes wrong, because it's your watch.
The idea was realisedly lunatical even back then, but party boffins really though that reality and laws of physics will yield to party's mandate.
The explanation that beidou 1 was a glorified, super expensive satellite pager, with navigation functionality as an afterthought does not hold water. This "explanation" came much later than the commencement of beidou 1 project.
The reason Beidou I needs two way transmission is they wanted add pager functionality to its navigation functionality. The party wants more control has nothing to do with Beidou I's two way transmission mechanism. When Beidou I was developed, it's mostly used by military. The party doesn't need "more control" there.
China already had military digital satellite coms working by late nineties. For them, it was of even lesser utility.
My point is that many things in China may be explained by the party wanting more control, but two way transmission of beidou I is not one of them.