Report from the class war

I note that the Federation of Small Businesses is up in arms over an Inland Revenue advert that demonises the self-employed:

The advert, publicising a hotline to report self-employed people who do not pay their taxes, depicts a plumber hiding under a kitchen sink.

The FSB states that:

We find it particularly offensive that the implication is that all self-employed people do not pay their taxes."

I share their anger, but wouldn't it be even better if the FSB were to point out that their tormentors don't pay any taxes themselves?