Service privileges for Patch Download? (Oracle 11gR2)
Short version: install the 12c software, create an empty database, and transfer the data with Data Pump. This way you can skip 11.2.0.1+ versions.

Long version: OTN Developer License Terms

In this, there is the following:


  No Technical Support
  Unless Oracle support for the Programs, if any,
  is expressly included in a separate, current support agreement between
  You and Oracle, Oracle’s technical support organization will not
  provide technical support, phone support, or updates to You for the
  Programs provided under this Agreement.


So no, you can not download updates officially with the OTN Developer License.

A valid support contract is needed for that. Actually a support contract costs extra on top of the database license, so there are companies that choose not to pay for it (and not to install patches...).