it's coz they offer two courses
B Computer Science and technology
B Computer Science and technology (advanced)
the BCST people don't do advanced subjects and BCST(adv) do them. Naturally the BCST(adv) will have a higher demand than BCST and students think BCST is just a shit course, but infact it's the exact same as BCST(adv) you just don't do advanced subjects. And if you REALLY want to do advanced subjects just beg the Head of IT and show him what you've done, he'll let you in