What is wrong with taking profit from their work? All she had a resource she wouldn't have been able to create value from no matter how much time she had in life.
I'll tone down the analogy so we don't go into abject examples that would still perfectly fit your point. You probably don't create that much value from your house, land, car, etc. But companies still aren't entitled to take them from you simply because they can make more money from them. If you are not willing to give them up for free you're contradicting your own point.
There's the mistaken impression that this is a 0 sum game and for companies to win, Henrietta Lacks and her family have to lose, it's expected of them. Or that the profits have to be exclusively on the company's side.
This wasn't accidentally obtained. They stole a winning lottery ticket and didn't share the winnings.
There are 2 aspects here. One is about ethics and privacy, someone took and continues to use these cells with no restrictions, like saying it's OK to have a slave because it was legal when you bought it. What other things are perfectly normal to take because you have more?
The second is financial, you're expected to pay through your nose for using a 5s song snippet but use a piece of someone's body should only benefit the the ones who took it. Blood donors get paid and that's nowhere near as unique as this.
I've seen people rationalize the Tuskegee syphilis experiment (people get syphilis every day anyway). Were you in her place you'd expect more of everything. More rights, more respect, more privacy, more money, etc. And I don't see anyone trying to fix past mistakes.