Why projects don't allow newbies to participate? We still ask a lot of questions and we're also noticeable

Because some of them only post meaningless they don't have enough knowledge about crypto currency, But some ICO accept newbies on signatures campaigns . Visit this site to look for it
https://bountylord.com/ .
Not all the time, i think it is because of the signature, for newbie they can't wear signature with links or changing its font and colors so giving a signature campaign for newbies might look useless because the signature they are wearing is not catchy enough to get the attention of potential investors.