I don't equate, say, "making money" with "stealing money". I mean the way people do things within the law. Inheriting is different; the money is already made. Interest is being useful to someone else, via the loan of capital.
Laws shouldn't be equated to ethics. There have been and will be countless ways to make money legally and unethically in any society.
The examples considered that: gambling, collecting interest, price gouging, underpaying workers, supporting laws to undermine competitors.
Gambling - I don't do it, but I'd need more specifics to see why gambling is bad in this sense. It's a voluntary pursuit that I think is a bad idea, but that doesn't make it illegal.
Price gouging is still being useful, just at a higher price. Someone could charge me £10 for bread and if that was the cheapest bread available, I'd buy it. If it is excessive and for essential goods, it is increasingly illegal, however. 42 out of 50 states in the US have anti-gouging laws [0], which, as I say, isn't what I'm talking about. I'm talking about legal things.
Underpaying workers - this certainly isn't illegal, unless it's below minimum wage, but also "underpaying" is an arbitrary term. If there's a regulatory/legal/corrupt state environment in which it's hard to create competitors to established businesses, then that's bad because it drives wages down. Otherwise, wages are set by what both the worker and employer sides will bear. And, lest we forget, there is still money coming into the business by it being useful. Customers are paying it for something. The fact that it might make less profit by paying more doesn't undermine that fundamental fact.
As for supporting laws to undermine competitors, that is something people can do, yes. Microsoft, after their app store went nowhere, came out against Apple and Google charging 30% for apps. Probably more of a PR move than a legal one, but businesses trying to influence laws isn't bad, because they have a valid perspective on the world just as we all do, unless it's corruption. Which is (once more, with feeling) illegal, and so out of scope of my comment. And again, unless the laws are there to establish a monopoly incumbent, which is pretty rare, and definitely the fault of the government that passes the laws, the company is still only really in existence because it does something useful enough to its customers that they pay it money.