The problem with holding another referendum within 5 years or so of the last one, is it does feed the short sighted goals of the pro-independence lobby. It does not serve the good of the country in the slightest.
We currently have a Tory majority in power. And they will be in power for the next 4 or so years at least. This isn't necessarily a government that Scots can get behind. And can have a huge effect on the result of any such referendum. Would a Labour government being in power have the same affect on such a referendum? I doubt it.
So the problem with having the vote too often is that it will be more heavily influenced by whatever government is in charge of the UK at the time. If you hold one less regularly, once in a generation, then the electorate can base their decision on the basis of what it actually means, rather than as an opportunity to get free of the current government.
Sure, maybe 55% of those polled would now vote for independence. But is that because we now have a Tory majority, or because people actually want independence? You have to be careful that any referendum isn't held so frequently that it has the possibility of becoming a protest vote against the current government.
Another referendum just now would be tragic. We have a Tory majority, and no opposition to speak of. That bodes well for the Nats. What if we had a strong Labour opposition just now? Would the polling be so much in the Yes camp? What if we had a Labour majority with Corben at the helm? Would the Yes vote still be so strong?
Obviously it's difficult to tell. But you simply don't want such an important decision to be based, in whole or in part, on the mood towards the current government. Which is why a decade between refs is a good thing. As it lets the people base their choices on more of an "average" of UK governments, than on what the current UK government is.
Plus, Jokester is correct. Salmond is a ****, and Sturgeon is a vile, vile woman. All the problems we have with our NHS, she is quick to blame the UK government, but not herself, who was Secretary for Health, over a DEVOLVED issue. The only thing she has said in the past few years that is actually of any value, is that we should do more to help the refugees trying to enter Europe. Beyond that, she is just a muppet.