I experienced both sides of that filtering by major. I took 6.001 and 18.001 freshman year. Scheme was great. However the first problem set for 18.001 convinced me being a math major was dumb. Why do rote proofs like A*0=0 for all A? I am always grateful I later took Arthur Mattuck's 18.100 which gave access to that mindset for people who didn't have it naturally. I am also grateful that I quickly learned what I truly enjoyed rather than having a long drawn out process to realize it.