That seems reasonable. There is a lack of reliable data.
But citing the ulterior motives of recruiters doesn't establish that it's safe to take counteroffers. There's no reason it can't be both at the same time: recruiters do have ulterior motives, AND it is dangerous to accept a counteroffer. Waving at the badness of recruiters doesn't dismiss the issue.
The risk of taking counteroffers isn't unconditional, it depends on the employer. The person evaluating a counteroffer has to consider the trustworthiness of the employer. In the best case, that still includes offering a lower-than-market wage (or how did you easily get a better offer?)
While it's true that recruiters' interests often aren't well aligned to the candidate's interests, employers' interests often aren't well aligned to employees' interests either. BUT... in these cases where someone is already desperate enough to be hustling for other offers to push their employer's hand, it's already a lot more likely that the employer's interest is less aligned with the employee than the recruiter's is.
Raises come out of profits and many people do take it personally and can't be professional and more importantly, decent about it.
If you are facing a counteroffer, you are the person best positioned to evaluate whether your employer is trustworthy - not HN commenters, not a recruiter and certainly not your employer.
I can see how people who hire on HN are scared of recruiter memes about counteroffers. A lot of us want to get rich and want shortcuts. Unfortunately, those recruiter memes align with certain realities. There is no shortcut, you (generalized you, not fecak) have to earn the respect of employees as a fair dealer if you want any rational person to want to stay or even consider your counteroffers. If you don't earn that respect, you have no right to complain: you deserve to lose the employees because you yourself adopted a strategy which puts a little cash in your hand in exchange for this very problem.