I guess I am missing the harm in this.
More tags, more chances my images are viewed.
What am I missing?
My take is if you don't tag your photos, it's sort of a non-issue.
But, if you are the artist and you have taken the time to choose how you want to tag your shot, that also means that you've taken the time to
not tag your photos in a certain way. For instance, I'll tell you what the photo is of but I'm not necessarily going to give you style tags - on purpose. So, if Flickr is throwing "Abstract" on my photo because I chose to either do something abstract, or worse yet because it can understand what it is, that's a problem for me. Heck, even if the nail the style, I may not want "Portrait" on something that's obviously a portrait because I do not want a potential customer looking at it and thinking I
do portrait photography.
Their evaluation of my work can point someone searching for a particular tag to a very bad example of
that style within my portfolio - even though it's anything but "bad" for every tag I've assigned - and my reputation suffers because they are trying to "help" me.
If they want to offer the service, make it opt-in for those who want to use it. Otherwise I'm happy to opt out of the service.
With extreme prejudice. 