Whenever you post please provide the full sql developer version that you are using and the full database version involved.
there is no way how to rename a sequence within the developer except of droping it and creating again (which of course nobody wants).
Righclick some sequence -> Edit -> Change name -> Ok
There is the RENAME statement for this, but Developer wants to run ALTER statement
As you said there is a way to rename a sequence within developer by using the RENAME command. The ALTER statement is used for the other attributes but does not support changing the name.
That appears to be the designed behaviour of the 'edit sequence' functionality since least version 22.214.171.124.
To me that is not a bug since when the dialog does allow you to edit the name and then displays a warning that it will drop and recreate the sequence.
You could make an enhancement request to suggest using the RENAME for this or add an option to allow a choice between the RENAME and the DROP/CREATE.