为什么wordpress序列化数据库中的数据？

Ok so im fairly new to wordpress programming and realized all their core data, and plugin data are always serialized. Doesn't this take away from the RELATIONAL aspect of a RDBMS? And it doesn't even save space because the strings are soooo long most of the time, and it's harder to scale/modify the data this way...Ok so im fairly new to wordpress programming an