I have 2" ABS coming from the basement floor, but the only drain kits I can find are for 1 1/2". What to do? I have looked for reducers but the only ones I can find are made up of multiple parts that add another 4 inches to the length. There has to be a better way. Right?

There has to be a better way. Right?
And so there is. A ABS 2" compression fitting, (see image) with a 2 X 1 1/2" Nylon Gasket will connect to your tub waste just fine. Good luck, Tom