URI Template: expanding lists

[Comment on the URI Template working draft]

Is there any particular reason why the current draft suggests that
variables typed as lists (marked with @) be expanded so that the
variable name is followed by a generated numbering?

The numbering scheme seems quite odd and specific (1-based with first
item unnumbered).

For example, in the case of the ? operator:

  {?@list}  ?list=val1&list2=val2&list3=val3

Why not simply expand it as:

   ?list=val1&list=val2&list=val3

This would still be a perfectly valid sequence of query parameters.
Or am I missing something obvious?

Christophe-