Disparaging emotion in yourself or in others is a perilous game
From an empirical standpoint, emotion—more specifically, emotional investment—is crucial for the development of a sense of meaning: meaning in 1) the existential sense, and 2) in the way it influences everything we think, say or do.
Emotions are preceded by meaning; they arise when things of significance—things that mean something in the pragmatic sense—enter our consciousness. Emotions are reactions to events, happenings, phenomena, facts; to experience.
One way to think about your question is as circular in causality: emotions influence thoughts, and thoughts influence emotions. Another way to think about it—a more helpful way, I think—is as emotions preceding thoughts. Our (emotional) reactions to phenomena entering our consciousness fundamentally impact the resulting beliefs, opinions and habits we form in response to that particular phenomena.
Emotions, therefore, are not just reactions but crucial sources of intelligence. Their structural impression on our opinions, beliefs, goals—and therefore, actions—cannot be forsaken; in fact, we can and should use it to our advantage.
Let’s take the example of existential meaning (or one’s ‘life purpose’). How do you know if the thing you’re focusing on is something you actually care about — not think you care about? If you experience unexplainable surges in motivation when you spend time on it, then you care. If not, then you don’t. Spending time on things you’re emotionally invested is the best chance you’ve got at living a life of intense, pronounced, and profound meaning.
Absent emotional attachment we humans are weak, meek, distracted, stupid, and apt to cave. Time is complicated, and discipline only takes you so far. Forced focus is exhausting, stupefying, spirit squashing, and pointless. Directing energies towards matters of interest is thrilling, energising, faculty enhancing, and always fruitful.
There is something practical to be learned from the unstrange phenomena that doing things we like gives us more energy and vice versa. Eschewing emotion doesn’t do us any favours.