But that doesn't make sense. If they wanted to make credible disinformation leaks, every half-way competent intelligence service already has it, or has access to it. And really, the one one country that has been positioning itself as a country that would do it is Russia, and they allegedly already have the information on trump discussed in the dossier. And trust me, it doesn't really help make leaked disinformation(or information, for that matter) more credible, because the same people they'd leak that information to already had the dossier.
There's also more you have to consider - do you think the American public did not deserve to know something that was both non-classified, and being heavily discussed about the (at the time) president elect by people at the top levels of the government and media? To quote Richard Tofel of ProPublica: "If you oppose the BuzzFeed decision to publish, you need to explain why citizens should not be allowed to see the dossier." CNN had already published about the existence of and key points of the Dossier, it was a matter of public debate - Do you really think that the debaters shouldn't be allowed to know what they're debating about?
For some further reading:
CJR defends Buzzfeed's decision to publish the dossier. Covers points I haven't covered here.
On the nature of Russian Kompromat, from Merril professor Sarah Oates.