It's not unethical or shallow to be persuasive. In fact, in a work setting, it makes sense to be in persuasion mode at all times, even at the water cooler (they still exist, right?).
What is persuasion mode? It's all about making your ideas seem compelling.
When you meet someone for lunch or for an interview, think about why you are even meeting. Get to the core. You might not be in sales, but you are selling something--an idea, a way of thinking, an attitude, an outlook. You are trying to persuade someone to like you, or to accept your viewpoints. In many cases, you are persuading someone that it makes sense to be around you at all, to enjoy your company.
When you send an email, you are persuading. Conversation on Slack? Yes. Skype call? Sure. Traveling to Bermuda on vacation with your family? Might be a stretch, but being in persuasion mode doesn't mean you are selling or convincing people they need something they don't have; you are persuading people you have something to offer beyond material possessions, and that fits into any situation or topic. Mostly, you are persuading them about you. In many ways, it's a leadership trait.
This played out recently in a conversation my wife had with her aunt. (Hold on, it applies--trust me.) They were chatting idly about how people make money these days, and her aunt mentioned how people have figured out how to dismantle farm buildings and sell pieces of them online for a profit, mostly because having wagon wheels and plank boards is "a thing" in Europe right now. It's an opportunity to make some side income, for sure. (If you start a company doing this, let me know.)
Here's the interesting part. This wasn't a conversation about anything too serious, but her aunt was in persuasion mode--to an idea, to a way of thinking and analyzing, to the details. Those who are not persuading are probably coasting or don't care that much about the people around them. It was persuasive in the sense that it make her aunt more interesting, and it made the time they spent even more valuable. The opposite of this is coasting; it's focusing on unimportant topics.
You can take this too far, of course. We all know people who are always asserting their opinion or trying to get you to switch from one political party to another. I'm not talking about that kind of persuasion. It's more about a desire to make yourself interesting to other people, to present ideas they have not mulled over before countless times, to make yourself a persuasive person.
The alternative is a terrible way to live. It's letting yourself be the one persuaded. It's making yourself into someone who is just walking through life without a desire to influence and viewing most situations as perfunctory. It's terrible because it grinds you into a pile of sludge, a person who accepts whatever comes about.
Success, in case you have not discovered this, is also all about persuasion. Mark Zuckerberg is persuasive. He has a view of the world he is persuading others to follow. Steve Jobs was always persuasive as well, trying to move people from complacency to innovation. Every famous person you can name is persuasive.
Getting into that sort of mindset takes work, though. You have to see conversations and meetings as an opportunity to persuade and convince. Once you settle for being the one persuaded, you hand over the reigns of success to someone else.
Take the reigns. Then, let me know if it works out.