Are they using the gpio/i2c/spi at all? Otherwise literally anything else is better.

Even if using those, if it's not in a robot or a weatherproof box on a pole or something, then a usb gpio dongle on a pc or mac makes 900x more sense.

The fact that something is done does not serve as an example that something makes any sense to do.

Using a pi for a computer is like when women knit sweaters for things that don't benefit from sweaters.