[timonoko]

"Invented by white christian missionary James Evans around 1840".

There seems to be no historical background or linguistic reason whatsoever?

Except there is this one reason: when English- (and French) -speakers made the phonetic writing system for Latin alphabeth, it became batshit crazy and quite unreadable.

[Rendello]

Syllabics are an abugida, so they map to the structure of Cree, Oji-Cree, and Ojibwe quite well. In these languages, syllables tend to have a single consonant followed by a single vowel (with some exceptions; this applies less in non-syncope dialects as well). Words that are unwieldy in the Latin script are less daunting in syllabics:

anishinaabemowin -> ᐊᓂᐦᔑᓈᐯᒧᐎᓐ

makade-mashkikiwaaboo -> ᒪᑲᑌᒪᔥᑭᑭᐙᐴ

[timonoko]

As is Finnish. And we do well. But the writing system was invented 600 years ago. So those Siberian-Eskimo-etc weird plosives and ingresses slowly disappeared, even if they were originally coded in the script.

As an anecdote: if the English had invented the writing system of Finnish, regular Goodnight ie "Hyvää Yötä" would have been written "Hiouaa'aa Io'ootaa". This is why these written Native American languages look so bad.

[timonoko]

I once tried to understand the Haida Gwaii writing system. I learned that Finnish/German "ä"-sound was written as "aa" and double "aa"- sound was written as "a'a" and quite normal-sounding consonants were frequently decorated with 'x and 'z to indicate some minute difference from English. Madness.