You might, but international travellers won't. The ones that do are either restricted by funding or are already so demoralised by the airport arrivals experience that they don't care.
If Stansted Express was cleaned up and redone with faster timing, and Liverpool Street was cleaned up from the dingy look, my view might change. Victoria is a great ending for the Gatwick Express, even if Gatwick Airport is not the most fabulous.
S.