I read the article and think that, in this case, I agree that the train company should have sorted out their seats better. I don't feel like the woman who refused to give up their seat should be either celebrated or blamed for her actions. Also, we're not talking about a 10-minutes bus ride here. The article is about a 7-hour train ride. Everyone wants to sit down there, understandably.
This woman reserved a first-class seat for her own reasons on a long journey, booked it well in advance and paid for it. It should have been marked clearly upon reserving that this seat was a priority seat and that she might have to give it up, so that she could reserve another non-priority seat if she wished. But it wasn't marked.
The elderly woman - who in the story sounds quite able to stand her ground, figuratively - could have booked a seat, which she did not do, or, if this was really out of her financial possibilities, ask for the seat politely and nicely. Also - but this is just me thinking - she might have just bought a standard ticket with a seat reservation instead of a first-class ticket without a seat, if sitting down was important to her and money played a role. But that's speculation.
It seems to me that both parties got worked up about it, in this case. Also visible because they got offered to sit down in standard area, but both insisted on the first-class seat. If I simply want to sit down, I'll sit down anywhere. But I think that the blame lies with the train company. It seems unnecessarily complicated to have priority seats sold to other passengers without any sort of warning. I book a seat on a long journey, too, because I know that it stresses and exhausts me a lot to be standing over several hours on a full train, and I wouldn't be happy to give up my pre-booked seat to another person either, because I have no proof that I need it. I would still do it, if I got the impression that the other person needed the seat more than me, but I wouldn't be happy about it.