BU is just a code implementation,
there are MANY
core, knots, fibre, bitcoinj, bitcoin ruby, BTCd, nbitcoin, statoshi, bitcoinxt, bitcoin classic, bitcoinunlimited... and so on.
That's a bit [purposefully!] inexact, don't you think? Most of the implementations you mention do not alter the protocol. Bitcoin Unlimited does, and in a way that's incompatible with the existing protocol. That is not "just another implementation".
Such dramatic changes should not be tried without a discussion and majority acceptance. I think even if the "censorship" problem was that dramatic as BU supporters describe, we're far away from that. Bitcoin's design has the flaw that it allows miners to change the protocol. If Bitcoin was Proof of Stake, then BU probably would have no chance to get near 50% of adoption - even considering Roger Ver.
Well, if I were in charge of Unlimited I would start it off as a fresh alt and forget forking completely. Their blockchain could start in a similar way to Clams, take an image of every BTC balance and start from there.
I would fully support that solution. I am currency agnostic, so if "BU-altcoin" is done that way (without premine or ICO or so) and really works as expected for a long time and I consider inappropiate the direction BTC (Core) is heading, I would perhaps consider even to change my usage from BTC to BU (if there is acceptance at the place where I am).