Why is bipolar a stigma but not depression?

What is amazing is how far we have come in eliminating the stigma of depression. It is now more okay than ever to speak of depression, to know what it is and even admit you might have it. But God forbid if you have something else. Take bipolar disorder for example, poorly misunderstood, feared, hated, stigmatized and generally a black mark to have, by our unforgiving society. Probably over-diagnosed in some venues, and yet missed in many others. The depressed part of bipolar, looks just like major depression, indistinguishable in that phase, from unipolar depression, that is why it generally takes on average of about 11 years for someone with bipolar to actually get the correct diagnosis, and therefore treatment. Plus it feels pretty good to be manic, till it gets to be a bit much. Sometimes the only subjectively bad part of mania is overwhelming anxiety. Objectivity can be lost by the sufferer.
Here is the actual problem that nobody seems to get, even lots of doctors/
Most people with a mood disorder do not fit into a perfect box or pigeon hole. There is a whole area or bipolar spectrum disorders that don't fit the classic DSM-IV definition. The so-called "soft bipolar' disorders. The truth of the matter is, it is on a continuum Hence for these individuals lots more antidepressants prescribed, remember it is easy to diagnose the depressed part. And whats great is that most of the antidepressants are approved by the government for treatment of anxiety. Except there is probably more anxiety associated with the bipolar spectrum problems than major depression. Antidepressants generally will stop working at some point for people with bipolar, or even make things worse. That is why correct diagnosis leads to correct treatment.
If you mention bipolar, the gloves come off. If you simply discuss "mood cycling", kind of like a roller coaster, except cycling enough to cause problems, then everything is okay. It is a safer way to say things. It gets away from labels, and the vicious cycle of stigma. It is more acceptable. Then you can get down to actually discussing treatments for the mood cycles. You don't have to argue about the diagnosis anymore, when you just treat the person, and their symptoms- One needs to get away from labels
Maybe the problem with Alzheimer's is similar, the same with dementia. Let's face it, there is still a big stigma, if there was not, we would be a lot closer to a cure. Perhaps if we called it something like "cognition slip" instead of Alzheimer's, people would stop reacting to it as if it is the plague or some black mark on one's spirit.