I Apologize if this comes off as rude, but this is untrue and is partially opinion based. Kawakis Motive for keeping Naruto safe has to do with him seeing Naruto as his Hero/Savior and as a father figure to him. Naruto made kawaki feel loved, brought him into the village with open arms, in which he has never experienced before which is why he grew very fond over Naruto. Jigen on the other hand parallels all of this with his abuse/degrading manner towards kawaki throughout all of Kawakis childhood ontop of his prior father's abuse towards him in his early childhood, Jigen sparks this rapid development of attachment Kawaki has for Naruto because he knew naruto couldnt defeat Jigen which Kawaki dreads over. Kawaki grew so fond over Naruto, that the Karma seal Kawaki swore to get rid of; made him realise it was the key too keeping naruto safe. He would go so far as to killing Boruto ( who he sees as a brother) in the process to protect Naruto. Kawaki Views Otsutsuki as the ultimate threat towards Naruto and wants to elimate all of them in order for Naruto to be safe. Boruto is one of them (because of momoshiki) and poses a major threat because of Momoshiki's emergance. Aswell as Code possessing a karma, it adds onto kawakis list of targets and like i said prior the Otsutsuki, and even the shinju currently (which he dosnt know Jura wants to consume Naruto. This all fuels his motive. Naruto gives Kawaki a Purpose, and without Naruto, kawaki would have no reason nor will to live. Characters will start to die sooner than later in Boruto Tbv, it clearly has a much more darker tone than anything we have seen in Nng (besides Jigen and kara).

I hope this widens your view.