It matters. And it isn't a 'nitpick'.
You honestly don't think it is worth clarifying what the 90% refers to because I can guarantee you that a lot of people who read your comment automatically assumed that Scotland consumed 90% of its energy requirements from renewable sources - which it did not.. not even close. It's also important for policy. You can setup a 1TW solar array, and it wouldn't be able to power one house at night. And that's the point here because we're trying to move from fossil fuels and the question is: can wind and solar do it? And the answer is no. Nuclear can do it. Hydro and geothermal can do it (but those are geography dependent).
>The US is not a renewable energy role model to anyone.
No. But Ontario is. We're one of the world leaders for carbon emissions from electricity generation and we are because of nuclear and hydro. France is ahead of Scotland too, and that's solely because of nuclear.
>According to wikipedia, Maine gets 75% electricity from renewables, which is among the highest of any US state, so they seem an odd example to pick.
Again, not from solar and wind. It's hydro. Whenever these high numbers are mentioned it's always effin hydro. The policy here was extending hydro transmission and crazy people trying to block it (meaning that capacity would be replaced by natural gas, not wind, not solar because they can't).
>What's more, with a population of just 1.34 million, Maine is clearly a complete irrelevance on a global scale, right?
It is irrelevant. We can't scale hydro to that level globally.