Spiner himself explained,
One of the ideas that John Logan and I had about what the next film would have been was a Justice League of Star Trek. Something would bring all the great Star Trek villains together, from Khan to Shinzon, and Picard is the only person who could stop them and he actually has to go through time and pluck out the people he needs to help him. He goes back to the moment before Data blows up and takes him back to get Kirk and Spock, and go even further back and get Scott Bakula’s character, Archer.
I can’t imagine it would have been good, but boy do I wish I existed in a universe where this movie had been made.
So as everyone else has said … yuck!
But then I quickly remembered “… All good things”. Time travel, big CGI thing in the sky, reuniting with old characters (Tasha, O’Brien) … and it works very well, especially as a send off.
I’m thinking that there’s a kernel in there as a farewell to TNG era trek. Maybe not something where Picard becomes a literal Time Lord, but more where a drastic event has forced time-bending onto everyone at the epi-center of the event and any attempt of take advantage of it also entails some cost and the only way to fix the “breaking of time” is to do something incredibly starfleet.
There’s no evil per se just things breaking and people taking advantage of it. And Borg 🤷 .