I think you're confusing the common meaning of rent for "rent seeking"[1] which, in economics, means specifically getting more resources in return for nothing. It's a pejorative definition.
Getting paid for a service is not rent seeking in the way people are using it here.
I actually didn't know about the pejorative nature of 'rent seeking', so genuine thanks for the link! IMO I didn't need to either, knowing the commonalty doesn't change the intent I was going for. Even if you're seeking rent above the break even point. I'd still say that's amoral at it it's worse ethically speaking. I mean to expose the hyperbole of the assertion that wanting to wake profit in of itself doesn't make you a leach. Manipulating the market, coercing a negative sum game (accepting a loss to force out competition because you can expend the resources). These are the immoral things people do. Pretending that, just owning property and having them gall to dare to not rent it at or below cost is what's immoral or unethical is harmful to persuading anyone currently undecided, that there are real harms with allowing malicious parties to abuse their capital to prevent others from even playing the game. Which is where the majority of the harms originate from. You dont win hearts and minds by lying about how the game is unfair, and anyone who dares to play is immoral. That's obviously untrue. The people that are cheating, or abusing the rules are what's unfair. And without the majority consensus we'll never be able to fix the defects in the rules.
Again, I think you're mistaking what people are saying.
> Pretending that, just owning property and having them gall to dare to not rent it at or below cost is what's immoral or unethical is harmful to persuading anyone currently undecided[...]
This is not what people are critiquing. No one else is talking about the thing you are. They are expressing their own moral judgements about a certain category of economic activity. That's why I linked you to a definition of "rent seeking." Economics does not make a moral judgement about rent seeking - it just says systems of exchange are more efficient w/o it.
Not everyone agrees on where to draw the line between productive business and rent seeking - but when someone speaks about businesses or owners "seeking rents" they are specifically talking about a proportion of their business that is past the point of making things worthwhile for them and into the range of excess. The definition of a "rent" in this context is that the business owner would make a reasonable profit without it. If they need to charge as much as they do to break even, it is not a rent (with some exceptions[1]).
There is another conversation all together that happens outside economics about how we should organize our society. The 'left' side of that conversation often includes the ideas that all landlords are bad or that profiting from property you own w/o labor is bad. Those are all ideas we could also talk about but they are orthogonal to the economic discussion. Economics cannot tell you what system of ownership is moral and morality cannot tell you what economic systems are stable.
[1] If an owner makes a bad investment and, say, buys a building at the peak of valuation, and then tries to pass on their bad investment to their tenants an an unethical way, that could be considered a "rent" in the economic sense as they are tying to get income on an unfair value of the building.
I think the point is that there is a structural issue with renting housing, in that most people who rent do not do so for the convenience of renting, but because they cannot afford to purchase. This creates a naturally exploitative relationship between the landlord and renter - the former is not providing a good (e.g. convenience) to the latter, they are holding the good (the housing) and then using the wealth asymmetry to extract rent.
Getting paid for a service is not rent seeking in the way people are using it here.
[1] https://www.investopedia.com/terms/r/rentseeking.asp