You're not wrong: simple macros can be written poorly. Macros which don't properly use GENSYM should be rejected in review. Also, it's entirely possible to write a hygienic macro implementation with DEFMACRO: nothing stops a team from doing that (or using one off-the-shelf).
But sometimes you do need the full power of DEFMACRO, and it's not possible to write DEFMACRO with DEFINE-SYNTAX. So one tool enables you to do anything you need, and the other only some of what you need. I know what I prefer.
Let's agree to agree then :) I much prefer Racket's macros. Their version of syntax-case is a bit simplified compared to the one shipped with other schemes like guile and chez.
But sometimes you do need the full power of DEFMACRO, and it's not possible to write DEFMACRO with DEFINE-SYNTAX. So one tool enables you to do anything you need, and the other only some of what you need. I know what I prefer.