It's a legal document. A lot of the length here is citations for prior rulings (take a look at Pages 3 and 4, for example). It's not "designed to confuse," but it also isn't intended to be light reading.
The TL;DR is that the SEC does not believe that the Grayscale ETF can meet the requirements stipulated for an "Exchange-Traded Product" under the Exchange Act. In particular, the SEC found that a proposed rule change that would have allowed for the ETF violated the requirements of the Act under Section 6(b)(5).
All of this is covered on Page 2. Subsequent pages cover precedent, various conditions under which other ETFs have been approved ("surveillance-sharing agreements"), and an extended justification for rejecting the proposed rule change.
The TL;DR is that the SEC does not believe that the Grayscale ETF can meet the requirements stipulated for an "Exchange-Traded Product" under the Exchange Act. In particular, the SEC found that a proposed rule change that would have allowed for the ETF violated the requirements of the Act under Section 6(b)(5).
All of this is covered on Page 2. Subsequent pages cover precedent, various conditions under which other ETFs have been approved ("surveillance-sharing agreements"), and an extended justification for rejecting the proposed rule change.