Of course you're entitled to your opinion, but I've read (and fail to find it now) that H&H's work in the 1920'2 wasn't that 'big' as you claim it to be. So, a lot of HJ should/could have remained.
Speeking of opinions, for me, scrapping an instrument with an historic importance as said organ in favour of a trendy new thing (described here already as being 'like' another one (Westminster Abbey) instead of being its unique self) is like a downright crime. Things like this happend in our country in the 1960's (I lament Anneessens 3x32' IIIP in Breda's former cathedral, scrapped and burned as it happened), yet we've learned (a bit); and I don't believe for a minute that this organ was beyond salvation/redemption.