Interesting question about the Scottish referendum. I don't know, but I suspect that also must only have been advisory. However, if it had gone to a Yes vote with a 48-52 split, then I would certainly have expected a similar amount of protest about the result by those who wanted to remain in the UK. It is always going to be more contentious to change the status quo than to keep it.
I also think the Scottish government were slightly better prepared as they had a longer time between announcing the referendum and carrying it out, although there were still many unresolved issues of course - eg lack of clarity over the currency.
Quite possibly, the Brexit referendum makes a future referendum on Scottish independence more likely, as those who voted no did so on the basis of the information presented at the time, saying that an independent Scotland may not be able to remain as a member of the EU - which they are not going to be remaining members of now anyway.
However, if that vote had gone the other way, I think it would have been fair to allow the Scottish people a say on any final agreement that was reached after negotiations. I don't see how you can enter into a process of negotiations of which you don't know the outcome and then just accept the final result even if it was not what you were expecting. Even Nigel Farage has said the way Brexit is progressing is not what he had expected and may well be completely crap for the UK.
In summary, yes the UK is rubbish at holding referenda! Unless it really is a binary question, with the new legislation already drafted (like in the repeal the eighth referendum in Ireland) then it seems they shouldn't be held unless you have a definitive outcome, rather than just an unachievable wishlist.