Why does Adobe not support tablets or Kindle Fire

You have it backwards.

Tablets (Kindle, Galaxy, iPad) don't support Flash.

Chronologically:

2008 (March) - Apple® releases the first iPhone, using iOS®. Steve Jobs is insistent and adamant that iOS® is NOT compatible with Flash® and NEVER WILL BE. Jobs' reasoning is that playing Flash® content is processor consumptive and it drains batteries, thus shortening the life of them in mobile devices. In six years, that hasn't changed. Not for the iPhone®, iPad® or iPod® Touch™. It never will change and there never will be a Flash Player® for iOS®.

2008 (September) - Google® introduces Android™ to compete with iOS®, for people who don't want to pay what Apple® is asking for an iPhone®. Android®, unlike its Apple® counterpart IS compatible with Flash®.

2012 (June) - Android™ (Google®) announces the end of support for Flash® with Android™ 4.3. Going forward NO Android™ devices will be compatible with Flash®, but older versions on older devices can still be loaded with "legacy" builds still available from Adobe®. Android™ (Google®) cites the same reason Apple® did for the decision to end support of Flash®. Adobe® continues to release security patches to Flash Player® for Android™ until September 2013, announcing the "end of life" for Android™ Flash® September 10.