I understood what you suggested initially and we may disagree, that's totally fine. I simply oppose your suggestion that the Subject of a topic should remain unchangeable for anybody else except the OP. You asked for opinions, you got mine. We don't need to find consensus.

Let me add another thought regarding consequences of your suggestion:
If the OP is the only one to define the Subject for the whole thread, I would assume that the Subject should change for every post in a topic when the OP updates the topic's Subject, no? (Of course, the Subject for any other poster could remain unchanged but does this makes sense when you allow the OP to update the Subject and nobody else can change the Subject?)

Now think about the following potential of abuse:
An OP posts a topic with some agreeable or interesting Subject. Other users chime in and post: Yay, I like your topic... totally agree... whatever...
Later the fictional malicious OP changes Subject to something really nasty and/or offensive and above assumed update mechanics is imprinted on any poster of the topic/thread. I definitely wouldn't want this.

I understood what you suggested initially and we may disagree, that's totally fine. I simply oppose your suggestion that the Subject of a topic should remain unchangeable for anybody else except the OP. You asked for opinions, you got mine. We don't need to find consensus.

Let me add another thought regarding consequences of your suggestion:
If the OP is the only one to define the Subject for the whole thread, I would assume that the Subject should change for every post in a topic when the OP updates the topic's Subject, no? (Of course, the Subject for any other poster could remain unchanged but does this makes sense when you allow the OP to update the Subject and nobody else can change the Subject?)

Now think about the following potential of abuse:
An OP posts a topic with some agreeable or interesting Subject. Other users chime in and post: Yay, I like your topic... totally agree... whatever...
Later OP changes Subject to something really nasty and/or offensive and above assumed update mechanics is imprinted on any poster of the topic/thread. I definitely wouldn't want this.

I understood what you suggested initially and we may disagree, that's totally fine. I simply oppose your suggestion that the Subject of a topic should remain unchangeable for anybody else except the OP. You asked for opinions, you got mine. We don't need to find consensus.

Let me add another thought regarding consequences of your suggestion:
If the OP is the only one to define the Subject for the whole thread, I would assume that the Subject should change for every post in a topic when the OP updates the topic's Subject, no? (Of course, the Subject for any other poster could remain unchanged but does this makes sense when you allow the OP to update the Subject and nobody else can change the Subject?)

Now think about the following potential of abuse:
OP posts a topic with some agreeable Subject. Other users chime in and post: Yay, I like your topic... whatever...
Later OP changes Subject to something really nasty and/or offensive and above assumed update mechanics is imprinted on any poster of the topic/thread. I definitely wouldn't want this.