Certainly.
However, spaceflight is getting cheaper by the year and is heading into a significant phase change related to costs. Soon the market will be dominated by partially reusable rockets. After a generation or two of improvements those reusable rockets will drive launch costs down by at least an order of magnitude if not two compared to today. That will make doing anything in space cheaper, and it's a fair bet that you'll see more organizations "doing stuff" (launching payloads) into space as a consequence (in fact, this is already happening).
Additionally, there are follow-on effects, especially when it comes to manned spaceflight. Take the ISS for example. Because it exists it means there is a call for services for it, such as crew transfers (Soyuz, formerly Shuttle, and soon Dragon/CST-100), resupply (Progress, Dragon, HTV, Antares, etc.), and module delivery. Lower cost launches would translate naturally to more activity in Earth orbit and more call for services, leading to a feedback loop of increasing activity. Within 20 years you'll see not just space stations but orbital towns and maybe even cities, as well as industrial establishments where R&D is performed on-orbit. Imagine how much more effective you could be at designing satellites and spacecraft if you had an on orbit environment that you could as a prototype test environment whenever you wanted to at low cost. All of that translates into orders of magnitude more activity in space at orders of magnitude lower marginal costs.
And in that environment, asteroid mining seems pretty sensible, not for service to Earth's surface but for service to on orbit activities. For one the equipment and infrastructure to exploit such resources will be cheaper to put into space due to lower launch costs, lowering the necessary price-point where profit is possible. For another, the customer base will be large and capable of making use of even bulk materials.
In that world, the world of 10, 20, 30+ years from now, asteroid mining will make sound economic sense. But the time to begin pursuing technology development is not 30 years from now, it's today. Building prototypes, figuring out what's possible, learning the early lessons as early as possible at comparatively low cost will give those operators a huge jump as changes bring their business into viability. Especially so in regard to the legal precedents in terms of laying claim to resources. For something that could easily be a trillion dollar a year, or more, industry in 30 years, that's an excellent RoI.