Every parents would have a specific reason. But for me, it was working mom.
Initially till class 6th, my parents did have that perception of tuitions being something only for weak students. My parents and extended family oversaw my daily homework and help me study roughly a week before exams. But around class 6th, it was hard for them to do it with both me and my sibling. Their work hours got longer too.
With science and math at class 7th was not easy for them to teach up xylem, phloem, chlorophyll etc. English was another barrier as they both had studied in vernacular languages. Eventually, my marks in exams were on the extremes, scored well on the subjects they taught well but fucked up elsewhere.
Eventually, I was started for Math & Science "co-curricular" for competitive exams, but then I was enrolled for languages tuitions (all 4 required coaching, even my mother tongue) in my neighbourhood especially as these subjects weren't scoring and brought the average down.