On the most basic level, the phrase implies that the answer given is the only answer to the question (by saying “the answer is…” instead of “Rashi’s answer is…” or “Rav Willig answers that…”). Saying “the answer” is a sort of conceit—and also, to me, comes off as uneducated.
When teaching a child Torah, it is common (and understandable) to pose a simple question, and then to give one answer as the answer. I remember learning this way in fourth grade, and being so proud to show off my knowledge to my parents. I had a question, and I knew the answer. Period. Children see things only in black and white—they cannot grasp the idea that there could be more than one correct answer.
Adults, however, understand the existence of multiple answers to Torah questions. The concept of shivim panim l’Torah is a fundamental component of our system. It is only those with some degree of intellectual sophistication who can understand that life is comprised mainly of shades of gray—and that Torah reflects this in the multiplicity of its perspectives. This idea is manifested throughout the entire system of Orthodoxy. It allows one to understand that there are many different valid derachim within halachic Judaism, and prevents belief in one’s own way to the exclusion of every other.
Religious fanaticism is the easy way out. It’s much easier to believe that there is only one right way, and that everyone else is wrong. It makes life simpler. It is also a childish and dangerous way of seeing the world. The basis for so much of what we believe rests in the idea that there can be more than one right answer.
Though “And the answer is…” seems but a harmless phrase, its philosophical ramifications are more complex and far-reaching than one might originally surmise. Though I don’t assume that anyone who uses that phrase has serious philosophical issues (since I understand that yes, it is only a phrase, and I shouldn’t read into it too much), the idea that it implies is deeply problematic.