Your question… is it a question? I’m so confused. You say Marius is Lestat’s maker and maybe that’s a typo, or maybe you accept movie!QOTD as canon, either way, it’s not my headcanon.

Lestat gave Louis the choice to be a vampire, because when Lestat was forced by Magnus into being a vampire, that was essentially a form of rape. Lestat tells Nicolas (TVL): 

“When it was offered me I said no. I tell you I said no. With my last breath, I said no.” 

The ramifications of rape are many and I won’t go into detail here, but it had an enormous impact on Lestat’s well-being, and in his relationships with everyone in his afterlife. 

Lestat wanted Louis to choose it, to WANT to be a vampire, he wanted it to be consensual, to spare Louis the damage of what Lestat had to deal with.

When Lestat teases Louis about his “whining,” it’s partly out of frustration; he saw in Louis a kindred spirit, and in book!IWTV he explained that killing was part of the deal, and Louis accepted the Dark Gift but then, fledgling!Louis was aghast at taking human life! In later canon, Louis’ “whining” is actually just putting up any rational resistance at Lestat’s ideas for adventure. 

VC itself was born from Lestat not having a choice when Magnus forced him into vampirism, in the sense that none of the books would have been written if Lestat had chosen NOT to become a vampire. If Lestat had died the night that Magnus kidnapped him, or been released and died later, as a mortal, he wouldn’t have turned any fledglings, Louis wouldn’t have been a vampire in the 1970s to be interviewed, Louis probably would have succeeded in killing himself over his remorse about the death of his brother… there would be no IWTV, no TVL,… 

But Armand would still have existed, as would Marius, and others who existed long before Lestat’s mortal birth. Maybe VC would have been about them.