I have a lot of respect for MariaDB, but they are aiming to be a drop-in replacement for MySQL. Drizzle is not a drop-in replacement and intentionally broke some compatibility to reach it's goals.
Not denying it, both projects have slightly different goals. But since some people reading this discussion might consider switching from MySQL to Drizzle it doesn't hurt to present them other options, which in some cases might suit them better (depending on what are your exact needs).
