I read the article and it doesn't make sense to me, but I wouldn't expect it to, as I know next to nothing about business. I however expect this to be similar

I read the article and it doesn't make sense to me, but I wouldn't expect it to, as I know next to nothing about business. I however expect this to be similar to the Siemens/Infinion Technologys split a number of years ago: there might have been administrative reasons, but at least as important was the appearance to potential investors. Siemens (and IBM) are huge, diverse, slow moving entities with comparatively stable outlook and correspondingly low expectations of gains, while Infinion (and the new former IBM Cloud entity) are younger, more specialized, riskier, but potentially much more profitable companies, which attract a different crowd of investors / investing strategies.