You're not giving over the rights, you're selling the right to profit from them under contract.

You can argue that contract law is essentially a battle of relative political and economic power, and IP and employment contracts will always be unfair unless limits are set by statute and enforced enthusiastically.

And personally I would.

But generally you're signing away the rights to specific text, not the insights or commentary in that text, and if you freelance there's nothing to stop you making your points through some other channel, and/or some other text.

If you're a full-time employee then the usual agreement is that your words (code) are work product and owned by your employer, and you're in that situation because your political and economic power is relatively limited.