Stop being so brown town about it, people can bump topics if they want to.
The most popular addons should not be hoarding the main page anyways.
People can damn well do what they want to. People can spam emotes if they want to, and yet we tell them not to do that, because it's stupid and a waste of our mental processing.
And in case you haven't noticed, there's no such thing as "popular addons", by which you mean (I assume) addon topics that stay on the first page without fresh updates. All threads die eventually, just like this one should have. If any addon thread ever stays on the front page for any significant chunk of time, it is because it is alive. Work is still going on. The main purpose of an addon thread is to release the addon to the forums. People can then suggest stuff, which may or may not be added to the living addon. If an addon thread is dead, stuff won't be added, and so suggestions/requests would be, by definition, useless and pointless, making the thread useless and pointless.
Once an addon is posted, and no more stuff is added to it, then it should become impossible to reply to so we can keep new, fresh, and living addons on the front page. This is expressly why topics become "too old".
