There was never any chance of federalism being on the ballot in the 2014 referendum. It was not possible for it to be on the ballot for the simple and rather obvious reason that a federal arrangement would affect the entire UK. Such a vote would have to be put to voters across the UK. It could not be decided by just one part of the UK. It was, therefore, definitively undeliverable. A referendum with undeliverable options is a farce.
The so-called ‘second question’ on the 2014 referendum ballot referred to an undefined ‘devo-max’ option. Alex Salmond did not want this second question on the ballot for another simple and obvious reason – it could only split the pro-independence vote. He spoke of being prepared to consider the second question knowing that this would be interpreted as him wanting it on the ballot and aware that Cameron would instantly reject it on those grounds alone.
Why didn’t Salmond just rule it out if he didn’t want it? Because, as you note, it was, according to polls, the most popular option. He didn’t want to be the one to deny Scotland’s voters the option they favoured. Fortunately, he didn’t have to. He got David Cameron to do it for him.
As to British Labour in Scotland (BLiS), their behaviour may seem inexplicable. Adhering to their anti-independence and anti-democracy stance is very evidently doing massive damage to the pretendy party’s electoral prospects. But they will not relent. Because they cannot. BLiS is no more than a regional department of the British Labour Partly and, as such, it is prohibited from standing in elections on a policy platform distinct from that of the ‘parent’ party. Party’s are not allowed to promote different policies in different parts of the UK.
As a British party, British Labour is part of the British establishment. It serves, and is in turn served by, precisely the same structures of power, privilege and patronage which serve and are served by the British Conservative Party. That is why the two, along with the British Liberal Democrats, so willingly colluded in Better Together/Project Fear. As British parties, they all prioritise preservation of the Union above pretty much everything else. Because pretty much everything that the British state is, pretends to be and wants to be depends on Scotland remaining in Britannia’s jealous grasp.
British Labour in Scotland languishes in the polls as it does not because it refuses to accept the democratic rights of Scotland’s people but because the Ruth Davidson made a better Queen of the Britnats than Kezia Dugdale. It really is as trivial as that. All the British parties in Scotland are squabbling over the British Nationalist vote. With abundant assistance from the British media, Ruth Davidson did the better job of being the figurehead for British Nationalism. BLiS has never recovered. I think we can safely assume it never will.