OK I know this sounds like a bit of a leap but let's be honest here - If done right, this show could be amazing for these particular reasons...
1. She's the best thing about Arrow
Obviously Stephen Amell is brilliant as Oilver Queen/The Arrow, but the majority of fans are part of the Olicity fandom. Olicity gives girls watching the show a role model. She's brainy, funny and a very relatable character compared to anybody else on the show. Felicity Smoak completes Oliver Queen. You see, at the very end of Season 3 of Arrow, erm, spoiler alert: That she took away the dark, serious Arrow and helped plant the seed for the true superhero, the Green Arrow.
2. It gives Arrow Season 4 a fresh start
Arrow Season 3 was the least impressive season of Arrow, but had one of the best components of the entire show to day; the growing of Felicity and Oliver's relationship. Arrow Season 4 will include a new villain and a crossover episode with former NBC show Constantine. This season, the Green Arrow will truly show his full potential and having Felicity around will only further push him into his goodness.
3. They can use her on crossover episodes without killing her
Come on! It makes total and perfect sense. Fans are always wanting more of her, while at the same time less, in order for more Queen so it would make having a spinoff perfect. Fans could watch Felicity for herself, and a bit of Oliver and vice versa without overfilling on either character. Her show could include superheroes, and secrets of the vigilante world she knows. Can you really see Arrow or Flash having a normal life without her? Um, nope.