I think there is more thread about 'quote', but I like to write something from myself what I noticed from multiple users.

As a campaign manager often I have to check users post history when they apply for join on campaign. I noticed that some users 90% post including 'quote' of other post. But whatever they quote it's not necessary in my opinions. I am assuming they just quote post because they want to make their post more larger.

I know you are allowed to use quote of anyone or from any other site. Its not against forum rules or trust system. But it's quite annoying for some users like me. I have been using quote wherever need. I don't know if someone will agree with me or not but I will describe below when I am using quote post.
1. I don't use quote if I reply on main post unless if there is some important part that I want to highlight.
2. If I want to give reply on any specific post then I just quote the specific part. I don not quote full reply as well.
3. Quote as a reference, sometimes some questions came that answer should with appropriate evidence. In that case I use appropriate quote as reference.
4. Remind your something, sometime it would necessary remind you something that were important, it would your own quote or my quote.

That's how I am using quote on forum. Hope newbie will learn how to use quote. It's quite important to make your post more quality. Unnecessary quote will discourage reader to read your post. So if no one read your post means it's not worthy to read and will look like spam. Improve your posting behaviour and do something good.

Because I believe  "today's newbies will be Legendary once a day, newbies are future of forum"