SQLyog is a Frontend / a GUI tool (or whatever you may call it!) for administering MySQL databases, and MySQL databases only. The very "idea" or "concept" of the program is that it should be a graphical interface for the MySQL native C-API. And the complete MySQL native C-API. And further implement routines for "batch-processing" for various administrative needs and smart and helpful interfaces to generate SQL transparently for user.
From time to time we are asked to implement support for commercial database systems (like SQL Server, Sybase, Oracle etc.) and various open source databases (like PostgrSQL, SQLite). But for each additional server system to support that would practically "double" the amount of code (except for the GUI elements, of course) or we would need to use a 'database abstraction layer' of some kind (ODBC or whatever)
SQLyog will connect to any ODBC database, but only for importing/migrating data structures and data from these ODBC databases into MySQL. Except for that we do not plan to support other databases than MySQL - including 'forks' based on MySQL code, whether Open Source like MariaDB, PerconaServer etc. or commercial forks.