There are some students who are very good at coding. They can crack any logic problem at their level. But they aren't very good at CS theory. They can code better than their classmates, but they're indifferent about the theory, displaying an attitude of "I don't care".
In this case, theory means there are various theory papers are presented in the syllabus such as "Theory of Computation" which talks about NFA, DFA, Turing machines, etc. Another example is Artificial Intelligence, which talks about ES, Fuzzy logic, etc.