Correct.
This encourages "split ticketing", now given that it's often cheaper to split anyway, that's not usually a problem. For example if doing a journey like York to the other side of Manchester, it's cheaper to split at Stalybridge.
That's not the case for all journeys though, for some people it is more expensive to split and they miss out.
The system is set up against people who buy longer distance tickets, but most rail travellers must know about split ticketing these days (and if they have not then they're probably driven to the roads - literally - by the ludicrous fares). That should change but I won't campaign for it because you know they are not going to reduce the price and increase the flexibility of longer distance tickets, they will instead increase the price and reduce the validity of shorter distance tickets.