I'm echoing OP's observations.

For instance, there was this BRG that was denied. The competitor was Hotelopia, and the hotel was in Thailand. In order to get around Hilton's BRG, the competitor added a clause which obviously is not enforced when booking: "you must be from Asia to enjoy the better rate."

And there we have it. Over 100+ countries from Asia and millions of people who can book that rate; not only that.. all you need to do is to switch to an Asian currency, you will get Hotelopia's better rate. No one from hotelopia is going to check your passport.

Hilton's BRG team focused solely on the "in Asia" clause. I explained that Hotelopia can easily put "all countries except Greenland" to circumvent Hilton's BRG. This is blatant undercutting of Hilton.com as well as other Hilton's Partners.

The Hilton BRG and Hilton Hhonors team were in the email, but did not bother to investigate this further. They simply chose to sweep the entire matter under the carpet. Very disappointing. This is very poor response, unfair to all of Hilton.com users, as well as other hilton's partners who did not use such underhand techniques their competitors. If hilton allows such practices and let it go without addressing it, what is the point of having hilton.com when it will never have the best rate?

The general consensus that Hilton BRG's team is doing their very best to reject BRG claims rather than facilitating claims has some truth in it.

I once booked a flexi rate, but compared a non-flexi hilton.com rate vs competitor's non-flexi rate. The idea is this, I do not wish to book the non-flexi hilton.com rate if the BRG fails, yet the BRG team has been finding ridiculous ways to deny claims. So I booked a flexi rate, but compared apples with apples. It was denied as well, as the hilton BRG team said I did not book the non-flexi rate, even though i compared the non-flexi rates as my comparison claims. SPG BRG team would have accepted it.

Given a few of HHonor's Diamonds have given feedback on their disappointment with the BRG program (myself included), I hope things improve, but to be honest, my feedbacks do not appear to have been heard.

If hilton.com is not having the best rate all the time, and instead of improving it, tries to find their very best to deny best rate claims, this simply drives loyalty away from Hilton as no one will be incentivized to become Hilton Gold/Diamond. And once people book from online travel agents instead of Hilton.com, there is no longer any reason to pick Hilton hotels over others anymore, other than pure pricing itself. There is no need to be loyal to Hilton.

SPG has a very strong BRG team as they recognised it is an important part of loyalty strategy. The current impression of Hilton BRG sounds like one trying their very best to drive loyalty away, without the team realising it, as the BRG team tries their very best to find the most ridiculous clauses and ways to deny claims.