Bad message? I don't know, even putting my preferences aside, I can't see where NaruSaku sends a bad message. Unless you want to count Sakura hitting Naruto, which is only for comedy and really doesn't matter, as much as antis want to say it does. I have heard arguments that NaruSaku is anti-feminist, but that doesn't make any sense to me. Like, how?
Gah! I can't stand that argument. "Betraying Sasuke" -- please excuse me while I barf. Sasuke doesn't care about Sakura's feelings and whether she loves him or not. He does not care. And besides that, Sakura doesn't owe Sasuke any loyalty since he turned his back on Konoha. Of course, that hasn't stopped her or Naruto from chasing after him, but that's just the kind of people they are. They're loyal to a fault.
But really, how would Sakura be disloyal by giving up a childish love for someone who never felt the same way? Real love isn't one-sided like Sakura chasing after Sasuke with a love that wasn't reciprocated. Naruto and Sakura have build a strong, sincere relationship, from friendship to something more, there's nothing "dishonest" about it or Sakura's feelings. Yeah, she loved Sasuke first, but her relationship with Naruto is deeper and more solid than anything she had with Sasuke.
The person I was talking with said that the bad message being sent was that whole the of "deserving" love. I couldn't help but laugh due to the absurdity of the comment. Falling in love with someone because they love you is apparently wrong, when your childhood crush has tried to murder you. The hypocrisy. The whole "anti-feminist" garbage comes from that scen in 630 where Naruto told Sakura she should rest because she just got done healing him. Naruto shows concern, he's automatically called a chauvinistic, misogynistic pig. Sasuke never shows concern, tries to kill her, berates her, and calls her useless, and he's Prince Charming. What a joke.
I hate that betrayal argument too. Sakura wasn't and wouldn't ever be disloyal to Sasuke if she fell in love with Naruto, if anything she would be betraying herself if she ended up with Sasuke, due to the fact that she has never been treated right by him. The last time Sasuke even complimented her was in the chuunin exams. He's tried to kill her more times than he's ever said anything nice to her, yet she's betraying him? Lol
I absolutely agree with everything you said.