Electro never felt like a deadly threat, even when he was controlling the city's electricity at the end, it was all slap dash rushed. Peter and Gwen have a quick conversation on how to defeat him. Team Spidey and Gwen go to the power plant and Electro's taken down. It was all just filler to set up Goblin's arrival for Gwen's death. The Times Square scene was just a joke. One of the worst sequences in a CBM.
Every main villain should have some effect on the hero. I'm not talking about them having to know them personally beforehand either. That's not a necessity as villains like the Joker, Bane etc have shown. They can impact the hero personally without having to have known before hand. I'm talking about having an effect at all. The hero should always learn something from the villain, or be affected personally by them in some way. Otherwise the villains are just there as filler for the action scenes. Every main antagonist should be a learning curve for a hero. They say a hero is only as good as the villain they fight, and that is so true. Which is one of many reasons why these TASM movies fail so much. The villains are horrendously bad.
Not that there's anything wrong with the hero and villain knowing each other or having a personal connection before they become villains. It's actually a common trope in CBM's. The Iron Man trilogy, Thor and Loki, Batman and Ra's and Harvey Dent, Cap and the Winter Soldier, Superman and Zod etc. And yes even in Webb's movies all the villains knew Spider-Man before they became villains, even Electro with his cheesy 20 second meeting with Spidey in the street where he develops his stupid obsession with him. It's all about how they're handled that's make it work.