Could you elaborate on the reform?

For some reason, I was under the impression that laptops in the MNT Reform series were the only laptops that were manufactured using open (source) hardware only. Or, if there were others, that it must have been doing something so special that they deserved to be put on a pedestal. But, currently, I don't feel confident enough to state why it would be superior over say the Olimex TERES-I or Pinebook Pro.

I hear the hype yet to me it looks like a severely overpriced tv box with some low-grade peripherials strapped to it in the least space efficient way possible.

We definitely pay a premium, but I don't know exactly why. Especially when the aforementioned Olimex TERES-I and Pinebook Pro are almost an order of magnitude cheaper.

Did they got rockchip to release sources instead of blobs or something?

From what I understood, Rockchip offers (at least some of) its SoCs as open source hardware. So, what MNT Reform did for the SoC is order them as open source hardware and include/publicize/provide all the schematics (etc).

What is the praise actually for?

FWIW, the open source hardware aspect is what I was intrigued by*.