There's a book I've probably mentioned before that's relevant to this discussion, it's called 'The Innovators Dilemma'. It talks about the concept of disruptive technology, something that isn't necessarily cheaper or better when it first appears, but can end up replacing existing technology because it eventually becomes BOTH cheaper and better. A good example is hydraulics vs. cable operated earth movers. The cable operated stuff came first, and was wide spread in the industry. A company thinks "hey, hydraulics would be handy" and makes a ditch digger (bobcat) for tractors. In the beginning, it's more expensive and less capable technology, but the company keeps developing it because there are advantages, including scalability and safety.
Eventually, the first big hydraulic earth movers start showing up. They aren't as powerful as the cable operated beasts, and they're more expensive, but they keep developing. By the time the cable-operated earthmover companies realized that hydraulics (which the had dismissed) were the future, it was too late for them to mount effective R&D campaigns. Not a single one of the major manufacturers survived the transition to hydraulics. Same thing happened with the transition from 8" HDs to 5.25" HD platters, or from 5.25" platters to 3.5" platters, except one or two companies survived the last transition because they saw what happened previously.
Laser hand weapons are currently less capable, more expensive, and less practical than chemical hand weapons. But will that always be the case? Consider this: No moving parts. Energy storage is improving every day. Toys that used to use relays and moving contacts to have blinking lights and make sounds are using little IC chips now because they're more reliable and cheaper to build than mechanical toys with moving parts.
With this in mind, I have no doubt that it's possible that cheap and reliable energy weapons will be in our future. The history of technology development pretty much guarantees it. They may not be 'phasers' or buck rogers death ray pistols, but the promise of lower production cost and higher potential reliability is hard to beat.
