Forums are designed for chat rather than a photo gallery and so are not designed to upload 30 photos to a post as this is unusual for most forums.
If you are wanting to show 30 photos then some type of gallery would be more appropriate rather than trying to add these images to a forum post.
The window to add an image to a post is designed around adding 1 image with lots of properties for that image, like width, alignment, spacing, preview etc. To allow multiple images to be uploaded this would need to be repeated multiple times making the window to add the image very large more like a long page with so many options it would simply confuse most people and just not be practical for a chat forum environment.
If you wanted to modify your own forum to add in this functionality then you can do so, but as this is not a requirement for most forums there are no plans to add this.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum