Hi birko70, and thank you for the comment!
There are several reasons for this choice.
There is a historical one, linked to the first implementations of BASIC language (towards which ugBASIC is compatible).
There are practical ones, such as the possibility of distinguishing commands and data/parameters without the need to identify them with a formal separator (such as, for example, a space), thus making programs more compact (and this is useful for BASIC 10 Liner contest )