[css-flexbox] and vertical-align

"Simple" question: why flexbox is not using existing vertical-align property?

Conceptually element under flex-direction:row is very close to
display:table-row/table element with display:table-cell children.
vertical-align works for such elements already including
vertical-align:baseline.

So is my question above.

If vertical-align for some reasons does not comply flexbox ideology then
how flex-item-align and vertical-align shall interact? For example what this
will mean:

el {
  flex-item-align: bottom;
  vertical-align:top;
}

?

-- 
Andrew Fedoniouk.

http://terrainformatica.com