No one is stopping public debate. If you want your view heard you have many options. Write to your MP or attend their surgery. Write to your local paper. Post something on social media on your own page. Go on question time, phone into a talk show on the radio.
If you want answers to your questions, listen to parliamentary debates and radio 4 interviews, read the papers.
What you can't expect is to be able to have your own personal question answered every time on every forum.
Unfortunately lots of people can't be bothered to do the most basic of research themselves - if they want an answer they immediately leap into Facebook. Often with some kind of half truth or misinformation either through ignorance or deliberately. This is not debate. This is spamming.