As mentioned in a comment, we had a similar question on ux.se about the Balsamiq editor, and there were three reasons to decline it:
- Allowing everybody to use it would mean making ux.se "that site on the internet where you can use Balsamiq for free, with no nag screens."
- It would also mean that everybody can post any image, because a) you can include any image in a mockup, and b) even if you couldn't, the image of the mockup is rendered client-side, so we cannot actually trust that an image that says it's a mockup really is a mockup.
- We would like new users to not rely on this tool too much, because good questions and answers should consist of more than just an image – it should contain explanatory text, with the image as an illustration. Thus it helps to have a tiny bit of familiarity with the Stack Exchange system before starting with mockups.
Now, on electronics.se two of those three are not an issue. As for 1., I got this email from the great people at CircuitLab:
I also saw this discussion on Electronics Meta: Why is the CircuitLab tool privileged?
We're fine with relaxing the reputation limit for posting a schematic if that's what you and your colleagues at Stack Exchange and the community at Electronics SE ultimately decide. Compared to Balsamiq, CircuitLab is already a free tool, so we have no problem with it on that front.
As for 2., due to implementation differences between the Balsamiq integration and the CircuitLab integration, we can actually be sure whether an image really is an image of a schematic.
This leaves only 3., and we have decided to give it a try regardless.
The schematics editor is now open for everyone, and CircuitLab schematics created through the integrated editor (and only those) are exempt from the "new users cannot post images" restriction. We'll be keeping an eye on it, and if it starts to cause issues, we may undo this change. But we're optimistic that it won't.