last time I did for different SCP, the person who responded didn't really help me improve the concept, and instead told me to come up with a narrative about it
That doesn't mean that the Ideas and Brainstorming forum is never helpful. If you happen to get an unhelpful critique (which does happen, it's not impossible) then feel free to contact a member of our Forum Criticism team to ask for additional advice.
Plus, everyone I've showed my draft in real life and in various online sites have all said they liked the concept
Do any of those people write for the site? If not, then their opinions might not reflect the response of the site community.
maybe I shouldn't value the criticism of people off the site, but still, I personally don't see the issue with the concept
You're not just writing for yourself here, you're writing for an audience who will be voting on your work.
Basically, I don't know what to do other than come here every 14 days and leave a post and only get one piece of criticism or very vague criticism every time
Use the IRC chatrooms, which many experienced writers use exclusively (most of us don't use forums that often at all because real-time feedback is something we work much better with). Contact a staff member for help if you repeatedly receive feedback that you can't work with.
I'll get it checked regardless, but I don't feel like anything will come out of it, and if it does I don't know if I will actually like it.
If you feel like writing for other people isn't what you want to do, this might not be the site for you.