Target synthesis is essentially the creative application of existing methodology.
The constant improvement in the efficiency and/or scope of existing methods, as well as the development of new chemical reactions provides a range of new and improved chemical tools that ultimately allow the synthetic chemist to devise more efficient synthetic routes to target compounds.
Research into methodology is vital to advance the field of chemical synthesis, which means it gets funding.
Total synthesis as an academic exercise, i.e. doing it because you can, is not as attractive an investment for funding bodies any more because it has no direct application - so fewer people work on it because there is less money behind it.