I think that and "Mass profits at Maine's Expense" were the big ones people were drawn too. And I think the pro-corridor campaign adding in the retroactive law aspect did more harm than good.
The question wording was a mess, too, which didn't help.
"Do you want to ban the construction of high-impact electric transmission lines in the Upper Kennebec Region and to require the Legislature to approve all other such projects anywhere in Maine, both retroactively to 2020, and to require the Legislature, retroactively to 2014, to approve by a two-thirds vote such projects using public land?"
This article did a good job breaking it all down, unbiased IMO.
https://www.mainepublic.org/politics/2021-10-22/what-maine-voters-should-know-about-question-1