If Yahoo end up being successful like, for example, Slack or Dropbox these security issues will not be at all discussed here.

I did not see any outrage when Slack security issues back in May 2105 [1]: majority of people were saying "but it is great software". Dropbox the same.

So Yahoo did a similar bet as all other companies (focus on features - we will fix security latter) but they lost that bet.

[1] http://www.makeuseof.com/tag/slack-hack-need-know-collaborat...