Why does the fact that Claudius does not stop Gertrude from drinking the wine condemn him even more in the reader’s eyes?

I think the fact that Claudius didn’t stop his Gertrude, well, his wife; from drinking the poisoned wine makes him such a worse person. First of all, he kills his own brother just so he could be king, which makes him very self centered and selfish. Then, he marries his brother’s wife, which is just flat out wrong. Also, he makes Hamlets life miserable, especially when Claudius doesn’t stop the queen from getting poisoned. Claudius is like everyone’s worst nightmare in this story, since he is the start of every single problem. If he wouldn’t have killed his brother, then Hamlet wouldn’t have gotten so mad and killed Ophelia’s father, then Ophelia wouldn’t have killed herself, which made Hamlet even angrier. Plus, everyone would’ve lived happily ever after in the end. Hamlet and Ophelia could’ve gotten married, since they wouldn’t have had the big fight, but then again the story wouldn’t have been as interesting without Claudius behind everything.