I have been following them on Twitter a while and the dev has stated a few times that they don't target Banjo as an inspiration, more going for Mario Sunshine, among other things. The weird thing is that they even have the name Banjo on their KS page, but especially now that Yooka Laylee is coming, it is actually nice to have different visions within this sub-genre. Would be boring if everyone was targeting the same thing. The fact that the development process is contracted and stuff didn't work out (the music thing) is not really that weird, game dev is rather chaotic. The issue is their shitty communication, which is probably a direct consequence from their size: Playtonic is a rather large studio, by indie standards at this point, where as Gears for Breakfast is, what, two three guys and I think only one of them full-time. It's a wonder they ever managed to get this far.
I don't get the negativity, seeing how the genre is so small these days and any half-way decent game should appreciated.