To be clear, you were applying for an internship (as you said in your post), and now you write "seems like I wasn't important". I'm not sure how we are defining important, but there are tons of people that apply for internships at places like Red Hat, and I'm not sure how many would classify themselves as "important" (or at least important to Red Hat).
I don't mean this as any disrespect to you, and companies should make efforts to make applicants feel comfortable and valued, but you are probably making more of a point for not sending specific feedback by your reaction. The sour grapes stuff is probably the most common reaction to the problem, and detailed or generic rejections can have that same negative result.
I don't mean this as any disrespect to you, and companies should make efforts to make applicants feel comfortable and valued, but you are probably making more of a point for not sending specific feedback by your reaction. The sour grapes stuff is probably the most common reaction to the problem, and detailed or generic rejections can have that same negative result.