Blocks are definitely treated as a problem. From the home screen, if blocking has a significant impact on queries it will result in extended Wait Time and/or Tuning.
Clicking on the Wait Time icon will take you into the Trends page and in the bottom half of that page you can see a tab for Blocking and/or Deadlocks where you can see which queries were doing the most blocking or which were the top waiting statements. Similarly, clicking on the Tuning allows you to see the top queries and clicking on those will identify how much wait time the query spent behind locks with a specific sub-section for blocking details as well.
In addition to the above, when viewing a specific DB instance, if you click on the "CURRENT" super tab, you can view the currently active sessions as well as any currently blocked sessions. You can even take an action of "Kill Session" on an individual session there if you wish.