I'm chill.
If CBS' post hasn't convinced you of the downfalls of accepting free gear then there is nothing I can really say to make the argument any stronger. If you want to gauge a sources product and service then accepting free samples is not the most effective way - it might be the most satisfying way because people want free shit. The best method is to anonymously place a paid order. You can learn a lot more about a sources service aside from just product quality by doing this btw...
Free samples are just another method unestablished / unproven sources use to draw customers - one trick out of many. They should be able to prove their worth without having to sling free samples out - you should be able to determine that without having to accept free samples too. Established sources can be easily researched - free samples not necessary. Unestablished sources are risky as fuck no matter what.
My barber sometimes charges me less for a haircut since I'm there frequently. I feel comfortable accepting that. If the coffee shop I regularly visit was offering a free cup of coffee to customers - most would probably accept that.
I don't however actively seek free shit - whether its from sources or any other business. I don't have an expectation of free samples and I don't need them to ease my concerns because It's not necessary and not really that informative / telling.
I sure as hell don't want to play a role in helping an unproven source get his start by accepting and reviewing his free gear. I don't want to be responsible for helping build up the clientele when he inevitably ends up fucking people over. Any reviews where the gear was given out for free are meaningless. They are even more meaningless when no disclosure is provided. At that point it's just dishonest.