I'm falling in love with the bass but can't afford one.

So I am obviously using emulated bass.

 

I want to go through the bass lessons in Rocksmith but they seem to be only accessible if you are using a real bass.

 

I don't get why this restriction has been placed in the game.

 

Any way around this?

You can get a decent 2nd hand bass for around $100. It is always better than emulated bass.

 

If you want to keep on playing emulated bass, I do not think you need to follow specific bass lessons. The techniques are similar for guitar and bass, you just have to get used to the different feeling. At least in my opinion.