I have friends (a married couple) who are incredible cheapskates, even though they are financially well off (pay cash for new cars, take expensive vacations, and own their house free and clear).
Wife made a remark about how it cost her $6 to send me a gift (of course she made the gift in a crafts class, she never buys a new gift for anyone). I let the remark go.
Then one day she was going on about getting a new cell phone plan. (They share a cell phone.) She was telling me the features they wanted, but most added features she wanted cost extra money. Finally, after listening to all this for quite a while, I said: “Hmm. Well, sometimes ya have to spend money to get something extra.”
But to call her cheap or say "Stop being so cheap" would have been rude.
By the way, I don't see the Cheapskate thread as posts from nasty, irresponsible, wasteful people. However, if a person isn't getting anything from a thread (useful information, enjoyment, even an occasional chuckle) or if the thread is just making them angry, they definitely should stop reading it, stop complaining about it, and move on