AMEN kriskhaira!!!
Often, when sharing to Evernote from Safari or Chrome (iPhone, iOS 10), I realize that I VERY MUCH need a tag which I didn't previously think of adding (therefore, I didn't add the tag earlier, in the Evernote app).
My not-great workaround has been:
before I tell Evernote to complete the Clip action, I type at the end of the Note Title the words that I'd love to add as tags. This is vastly less preferable to being able to add tags, because when I later search in the Evernote app for one of those words, the results contain every single note which just happens to contain that word (and yes, this happens when I limit my search to within only 1 notebook).
I was an extremely early adopter of Evernote's software (basically, when it first launched), and have been very happy to experience its transition from a rather confusing and limited desktop interface to an intuitive, multi-platform essential tool :-) Now if Evernote could just add the ability to create a new tag from within its share/clipper... ;-)