Nice comment. I'll address individual points.
Multiple times you inferred that all teenagers are the same.
There is no real way around this at your age
'No teenager can get past this.'
Pro-tip: all the websites are correct. Your writing does suck. How do I know this? I've never read your work.
I'm not sure what exactly your point is here, but you did agree with the generalisation absolute that, because he's a teenager, his work sucks.
In this case, that would be a lack of an ability to relate, think critically, and carry a cohesive idea for two hundred pages or more.
Something about this one struck me as off, like you thought teenagers were another species. Yes they're developing mentally, but that doesn't mean they're unable to empathise or think critically. It is a generalisation absolute to say that teenagers can't think critically or carry a cohesive idea for two hundred pages or more.
I think you are wrong about the details of one's life leaking into their writing. Your imagery is lovely, and your writing is very nice, but that doesn't make it right. Also you came out with the line
The job of a writer is to allow others into their mind and heart and make themselves at home
which I completely disagree with. I'm not writing because I want people to get into my heart and mind and make themselves at home. In my writing, people do not get into my heart and mind and make themselves at home. I write to tell stories that I want to tell. You have not read my writing, so you don't know if details of my life leak into it. Every author who's ever successfully wrote with a pseudonym, who has fooled people into believing they're a different gender, would like a word with you on that. A novel isn't brain surgery and a fiction book isn't mental naked-times. It all sounds very nice, but it still isn't true.
You say you don't feel superior because it sounds bad to think yourself superior, but all you have to say on the matter is 'young people are creative', which is purely your opinion, and isn't backed up by any facts (also, you're clearly not 'sorry to say' so there's no point in saying so). When I was younger, I was idiotically creative, in that I came up with rather ridiculous things that I thought were awesome, but were actually what thousands of other young children were thinking as well, which makes it rather uncreative. Then look at an older creative person, say Brandon Sanderson. A lot of children could not match his creativity.
Maybe you changed a lot from 17 to 18, but you can't expect everyone to follow you. Some people change in much smaller ways, and keep lots of their personality despite growing older.
Well that whole generalisation vs absolutes is very pedantic, but your general (hah) point seems to be 'absolutes are bad, and I didn't make that many of them'. The ones you did make, however, those were the ones I was addressing. Hopefully that's that solved.