Winston's parents were big supporters of superheroes. So, when he and his sister inherited the company, they continued this support and decided to take it to the next level, kicking off a campaign to help the Supers' cause. Since the government shut down the program that helps supers, the time was right for the Deavors to step in.
Ultra-wealthy, savvy and suave, Winston goes big in everything he does, including his plan to bring back superheroes. All he needs is a hero (or three) to help him change public perception and eventually make them legal again. His reason for choosing Elastigirl to lead the campaign was because she tends to solve crimes with far less damage than her husband, based on cost-benefit analysis by his sister.