Electrons are fermions which means that two electrons can't occupy the same quantum state (Pauli exclusion principle). Bosons don't have the limit so I believe that implies that you can have stronger signals at the low end since you can have multiple photons conveying or storing the same information.
What the previous poster is implying is that electrons interact much more strongly than photons. Hence electrons are very good for processing (e.g. building a transistor), while photons are very good for information transfer. This is also a reason why much of the traditional "optical computer" research was fundamentally flawed, just from first principles one could estimate that power requirements are prohibitive.
