Why are dictionaries disallowed for attribute types?

[saschanaz]

9e764b7 disallowed it but with no background. Does anyone have an idea why?

(Found it from w3c/deviceorientation#90)

Edit: I guess because they are also copied as sequences are?

[domenic]

Yes, because they are copied as sequences are, so you'd fail to have x.attr === x.attr.

[saschanaz]

Thanks!

Currently the sequence section says it's disallowed for attributes but the dictionary section does not, so the work item here would be add a corresponding prose with notes.