I strongly disagree. Mostly because the semantic web is very, very useful in the life sciences. And over the next 5 years will save more money being wasted in this field than was ever spend on grants for the semantic web tech. Not just on the academic side but also on the big pharma side.

For the rest I would say this holds true for to much of any CS research e.g.: Grid, Cloud, P2P and GPU compute. Looking at the vast sums spend on this the practical benefits are from outside the academic labs. I.e. all those other buzzwords that are used to justify grants.

OWL reasoning at least standardised the format of many logical constructs and allowed for competitive improvements. Now you can at least change your prover while maintaining your axioms. So you get something like StarDog which is vastly better than the Pellet you are probably familiar with.