It's not just for legacy purposes. I've written a few useful personal tools in Purebasic, for instance. BASIC dialects tend to provide the functionality needed and can be handy for quickly throwing something together when you don't have the time to deal with GUI frameworks and complex libraries. You can also use Python or Go, of course, but they do not have integrated IDE and do not have a rich command set in the core language. Easy deployment and compact executables are also a plus of some existing BASIC dialects. If I had the money / the investment in a license would give me a good ROI, then I'd also pay for Xojo, for example.
Whatever gets the job done without wasting time.