The reason those high profile members support BU is very simple - their money lay Not in bitcoins now, but in some altcoins like Eth, dash etc. Even Buterin (guy with some programming skills) mumbles something against Segwit and LN, he understands what it'd mean for his alt.
Consequently they don't want any good for Bitcoin, because if Bitcoin green all forks are red.
A very balanced view, full of knowledge and love. Genius!
Don't you want to relax a bit? It feels better. Have some beer, some sex.
Apart from that, every time when Bitcoin went down in price altcoins soon followed. So that's not an argument.
And: Let's have UASF. But let's try to bring more people on board. At least, F2Pool.