Well a TIP41 is not a "fet/transistor", it's a BJT NPN power transistor. And yes one can use it instead of logic level MOSFET, and many of the driver circuits in the arduino playground show NPN transistors used as low side switching transistors for driving things like leds, motors, solenoids, buzzers, etc. However logic level N-channel mosfets are the best choice these days as they have such a low Ron spec that they dissipate less heat then a typical NPN power transistor.
I'm aware of the differences, I was asking why you couldn't use a power MOSFET or a power transistor instead of a logic MOSFET. You only want a on/off application which can be done by saturating the gate or base, requiring only 1-2 resistors for current protection.
I admit I haven't looked up the price differences between a logic fet and a power fet but I would assume a power fet is cheaper.