First, I just want to clarify some things, I hope no one gets offended. Usually, it takes time to put out a new chapter because of all the work involved to present a chapter with quality (cleaning, redrawing, quality control and all the other time-consuming stuff). Also, most groups have other projects, so their efforts aren't only in releasing one chapter and that's why it doesn't come out as soon as the chapter is released in the raw source.
Besides that, some groups are published chopped chapters because it's the way the Japanese published it's doing (Most comic-walker mangas are being chopped in 1.2,1.3,1.4) and so instead of letting everyone wait one month for a single chapter, many groups are deciding to release in the same way that the publisher does.
I hope this clears some things and again no shade against anyone. Just some information that I gathered around my years in here.