Is learning Drupal 7 a bad option now after release of Drupal 8
Well, firstly learning never gets wasted. Whatever you learn will some day in some moment help you. 

Yes, Drupal 8 is going to be released and not yet released. No one knows when it gets released and even people are skeptic about the features that vary with Drupal 7. Definitely, Drupal 8 is going to set a new standard in development and usage. But, till then we shouldn't avoid Drupal 7. 

Previously, we developed a website in Drupal 6 as soon as we deployed the site Drupal 7 was released. Then the features provided by Drupal 7 attracted us and we started migrating to 7 and it took most of our time in migrating. But our knowledge and work in drupal 6 didn't go into vain. Infact, we just learnt the new features added/upgraded. It took us only 1-2 days to know about Drupal 7, as we know the core concepts. 

So, I suggest you to start learning drupal 7 don't bother about the things that are yet to come. You can easily manage things even drupal 8 gets released.