The "after you gave notice" part in particular is quite stupid. It will simply encourage people to wait longer to give notice, or not give notice at all.
Were I leaving a company amicably and had no other constraint on my time (say I'm planning to start my own company, or even just take a couple years off), I'd give several weeks, if not a few months' notice, to maximize flexibility for everyone. If I knew it was going to screw me out of $10,000, however, I definitely would not extend that courtesy.