I beg some people within this thread to internally ask themselves why seeing the teenage adventures of Kamala Khan makes them think, "This is for teen girls only," while the teenage adventures of Peter Parker is met with, "ah, this is for all ages and genders!"
I did exactly what you asked (internally asked myself why) and here is my very honest reply.
Also FTR not trying to be defensive here as I'm actually enjoying Ms Marvel thus far despite it feeling very YA to me.
I should state I am also born and bred in NJ and actually lived in JC for a year and a half when I went to college in NYC and could no longer afford Manhattan.
I'm a sucker for whenever Jersey gets any shine so I would be watching Ms Marvel strictly on the strength of it taking place not,only in NJ but also a city I not only grew up by but also lived in for a little while.
I personally have a higher tolerance for Spider-Man feeling more YA as he is a character I have grown up with damn near the past 50 years.
I am 47 years old and saw my first Spider-Man comic when I was 2 or 3. I was attempting to draw him when I was 4 years old.
Spider-Man to me is a beloved character who has been a part of my entire life and also happens to be synonymous with Marvel itself.
So while I no doubt also feel the movies that revolve around him also feel very YA, I am more lenient and accepting with that fact as I actually very much equate being a fan of the character with my entire life, especially the younger part of my life.
Simply put, nostalgia is a hell of a thing.
Kamala, since I do still read some Marvel comics on occasion (I skew way more "indy" and have for the past 25 years), I am aware of the fact she is not a brand new character, I also knew she was from JC and is Muslim, but that is basically the extent of my knowledge on the character. I've never read any of her comics. So truth be told even after watching and enjoying the first 2 episodes, I still am not sure (yet also intrigued) by what her powers actually are.
This is why I no doubt feel more aware while I am watching her show it has a more YA feel to me. I am less lenient towards accepting this fact as I have no nostalgia of emotional ties to her character itself. So it is way more apparent to me it feels YA.
Again to reiterate , I am also aware Spider-Man also has a YA vibe as well, but it is easier for me to accept simply because it is a character I have known and loved not just since I myself was a YA, but since I was a toddler and infant.
And it really is that and nothing else. I am still watching and enjoying Ms Marvel. It is just a bit more difficult to accept the YA vibe as an adult.
And honestly I was not even going to reply as your comment is posed to me in a way to be more of a gotcha statement and there is only incorrect answers to it. However I really do not think that is the case for myself personally.
I just can more easily accept that Spider-Man also has a YA vibe to it because I have literally grown up with the character and because of that and my attachment to the character always being a part of my life, I am way more lenient and willing to overlook the fact that he too feels pretty YA and there is no denying that fact.
Really hope I explained that all so it makes some sense and did not come off as defensive or whatever. That is not my intent. Just truly trying to explain that why as a 47 year old while I recognize both character have a YA vibe to them, it is much easier for me to overlook Spider-Man since he has always been in my life. And I no doubt recognize a lot of that is on me. Just as I said, nostalgia is damn powerful.