Patents have other uses other than stopping third parties copying your designs; my company uses IP for the following: -
To allow entry into a market that requires products/design with IP (our industry is regulated in some territories, especially ones which carry government subsidies).
To remover barriers to market (i.e. by having a patent it means that we are not infringing anyone else's designs and are therefore free to trade).
To create a portfolio of IP that is of value to current/potential investors in the company.
To support marketing efforts/collateral - 'patented product', or 'patent pending' carries weight in the eyes of the customer.
To gain recognition/awards - out patented products have helped us get a Queen's Award for Innovation.
A history of patents/IP gives us credibility when applying for grants and other external funding.
We are in the UK, so profits from patented products receive a tax break.
So for us at least, definitely not worthless