It has a Hebrew version on Scumm, and it is basically the same version here, so why no Hebrew installer?
I think Gog has no love for Hebrew translations, I never saw a Gog title with Hebrew Including Simon The Sorcerer titles,
But this is even not a license issue as those are all freeware files so why not include it :(

I would imagine the number of Israeli GOG users isn't justify getting the Hebrew versions and if to be honest most Hebrew translation are rather poor in quality (though I would still want to see them here, if only for nostalgia purposes). You could try writing support on the subject but I doubt it help much.

Incidentally, the Hebrew translation for the Simon the Sorcerer game in available in the ports to Android and iOS, so it's not impossible to get them.