Take your expectation to the bank or the supermarket and see what it gets you.

If I bet $1 and lose but get a 20% discount I have lost 80-cents.

If I bet $1 again and win, I win $1.

I still am down 20-cents.

Where is any of that positive? How does that 20% discount on losses improve my expectation?

A loss is a loss whether it's a 100% loss or an 80% loss.

Losses do not create gains.