Why password change is shown to everyone? I mean what purpose does it serves to tell everyone that X user has changed his/her password in YY period of time? isn't it a good practice to keep our password changing frequently or this doesn't apply to this forum?
I'll explain it to you in as simple terms as I can.
Consider a situation :
You agreed for a trade over 10 bitcoins with someone in bitcointalk.It's obvious you wouldn't know them personally so all you have to trust is the bitcointalk account.
Next day,your account gets hacked,your details are changed and hacker immediately messages your trader guy as an imposter and redirects bitcoins to his address.
Two situations :
1.If password change wouldn't be visible to anyone.
Other trader party would never know if there is someone else behind your account.
They will give no second thoughts since there is nothing suspicious about it.Only after the hack and money transfer when original account holder posts from a new account you'd realized you have been ripped off.
2.If password change is visible [the current scenario].
Before the trade,change in sudden plans or address changes would quickly give you hint to check out their profile to see if the password has changed.If it's changed,you'd be extra careful sending them coins.If smart enough,you can ask for a signed message from the oldest staked address.Saves you from lot of potential scams.