In late position, first in, your K-Q might very well be the best hand. Over one limper, you might have a race against a smaller pair or face a weak Ace (assuming skilled opponents.) If on the other hand the pot is raised, and you look down at K-Q, even K-Q suited, you should fold, unless the raiser accidentally shows you his cards, and the implied odds are significant.
When the pot is raised, the possible hands held by the raiser tend to dominate K-Q. In fact the only hand you could possibly have the lead on is Q-J. You are probably behind every other hand held by your opponent. You may only be slightly behind but profit in poker is based on small edges. Why give your opponent the edge? If your opponent has a real hand, your two paints are in real bad shape. Let's examine all 173 possible hands.
5 hands: A-A, K-K, Q-Q, A-K, A-Q. You are in bad shape, and these are the hands that are quite likely if the opponent raised.
6 hands: Pocket pairs, Jacks to sixes. Players often raise with these but they are favorites against your K-Q even if your paint is suited.
4 hands: Small pocket pairs 5s, 4s, 3s, 2s. Here your suited K-Q might be a slight favorite but K-Q off suit falls behind.
10 hands: A-x. Some players might raise with these but you are still an underdog even though a small one.
148 hands: All those hands you are ahead of, like Q-J, K-J, K-T etc. but who raises in early or middle position with these hands?
So the next time you are faced with a raise holding K-Q, take a second. Do the odds really warrant a call in this situation? Are you behind, or are you way behind? Do the implied odds really dictate a call or should you wait for a better spot? You are only ahead if the raiser is on a steal, or a fool.
You make the call.