I haven't read CH's post, but Jane from British Beauty Blogger has written a very thoughtful post about all this and it is worth reading. (Love her!) Essentially she couldn't do her job without the free samples that she is sent. Her blog is mainly about showcasing and reviewing new releases. I have always found her very open and transparent and she also offers her readers a choice between affiliate and non-affiliate links. I have not seen anyone else do that. She also mentions that the rewards from affiliate links is not as much as people think and she gives an example of earning (sorry can't remember exact figure) £100 for £6k worth of sales. I actually think the brands also have a lot to answer for and their practices should be reviewed.
Ultimately, it always comes back to that transparency for me, if you state all products I get are sent to me to review for free everyone knows where you stand. The reader can then make up their own mind if they trust the reviews or not.
I think things become more murky when Influnecers (that term needs to die!) dabble in a bit of everything. A lot of them cover interiors, beauty, fashion, general lifestyle and therefore I think it is important that they clear what has been gifted and what hasn't. There clearly is a difference between being sent a lipstick and the brand hoping it will get a mention or review to someone swanning off to the Maldives for a paid for holiday.