This was bought up here before: Note type versus note type · Issue #237 · ankitects/anki-manual · GitHub
Do we want “Notetype” or “Note type”? Seems the importing screen in Anki uses the former unlike rest of the app. Not a huge issue but it’s best to be moving towards all “Note type” (but I think you still disagree?).
There’s certainly a hodgepodge of the two right now, which I’m think we can all agree is the least preferrable option.
If we’re going to take popular opinion into account though – let’s really do it!
Not a large amount of votes, but there appears to be a strong preference so far.
I know you were hoping it might land differently. 
For a bonus point in favor of note type – it’s probably a lot easier to translate consistently across languages.
Since “notetype” is a made-up word** [
… non-lexicalized compound noun], in most languages I think the first thing you’d have to do is split it up again and translate the words separately. Whether you’d rejoin them after that could depend on a lot of factors – the grammar rules in that language (e.g. whether and when joined compounds are allowed in the language, genitive construction), the style/skill/experience of the translator (e.g. translator deference to the lexicon of the original text), etc.
** no disrespect intended – most words are at some point!
From a programming/design perspective, I still find ‘notetype’ clearer, but I guess we could always have some policy like “‘notetype’ internally, ‘note type’ for user-facing terminology”.