No, the surcharge is optional. Only students who want to upgrade their VRR and NRW ticket to the Deutschland-Ticket will have to take out the additional (monthly) subscription.
If you only travel in NRW, the regular semester ticket remains your best option.
And even if you have subscribed to the Deutschland-Ticket, you can cancel it monthly. The only mandatory costs included in the social insurance contribution are the fees for the semester ticket (> VRR and NRW ticket); they are paid by all students out of solidarity – including by students who don’t (want to) use the semester ticket at all.
That’s the only way we can afford to provide the semester ticket for our students.