I would say I'd agree with that statement.
In order to conduct a research, we need do several things:
- Collect the fundings
- Collect the subjects
- Gather talented researchers
- Bought the place and equipments, etc.
All of the things above require a high amount of investment. So, one of the argument is that the research that initiated should at least be applicable into real life to the point where the researchers could recoup all the investments that they made to do the study.
Second argument is that by definition, science study various aspects of our natural world through observation and experiment. Since something that purely theoretical is still not part of our natural word, we can say that researches based on theoretical problem non-scientific.