I don’t think he’s calling your specific reviews into question (I could be wrong).
As you may or may not know, many American-based amateur reviews where the reviewer has been given a product will include a disclosure stating something to the effect of “This product was given to me free of charge in exchange for my honest review”. You see this a lot on Amazon, for instance. By and large, these reviews are far from honest, and are just glowing endorsements of whatever product the reviewer has been given. It’s gotten to the point that using that kind of disclaimer kind of casts shade on the legitimacy of a review.
To be fair, most of these reviewers are just folks. They were offered, often out of the blue, something free if they’d write a review. More often than not, the company rep will even tell them to be “honest”, because they understand the psychology of the situation. Tell a stranger you’ll give them something for free in exchange for a good review, and all of a sudden, somebody who hasn’t written a thing in their life will be full of indignation at the idea that their endorsement can be had so cheaply. But ask that person to be honest... Well, people are social creatures. We want to please. We feel obligation. The vast majority of first-time reviewers will write glowing reviews of whatever they’ve been given, expound on how wonderful the company is, and gloss over any negatives, no matter how glaring they may be.
Hence the stigma around the disclaimer “This product was provided to me free of charge in exchange for my honest review”.
It appears you’ve written several reviews, and the process is something you take seriously, so I’d just stop using that red-flag of a disclaimer, if I were you. Or, if you actually value your reviews more than a bit of extra cash, you should probably also stop taking free gear, at least until you decide to go pro and get a bit larger.
Speaking of pro reviewers... A well-respected reviewer has the clout to hate something and still command free stuff... Their take on something can move merchandise, so companies seek to impress them rather than the other way around. If they don’t like a pair of cans they got for free that’s okay, the company will still send the next gen, and hope it fares better. A smaller reviewer doesn’t have that clout... If they give a poor score to something they got for free, it’s very possible the next gen will not be forthcoming. A larger reviewer knows that there will be more free gear to review, regardless of whether or not they like something- so they can effectively eliminate bias from their reviews. While a smaller reviewer, who knows that if they don’t give something a good review they won’t be getting anymore gear, cannot completely eliminate bias... There is a vested conflict of interest.