The consent form really plays a lot of roles and some of those will resonate with your client/company/coworkers/boss better than others.
For example, it may be more effective to explain that the consent form helps protect your company from getting sued. The consent form also helps make sure your research is above board and in line with best practices. And it helps you build better trust and rapport with your participants, which in turn will enhance the quality and reliability of your findings. Yes, it also protects the participant, but leading with that as the purpose to use it does come off a little aggressive - to your colleagues it may have sounded like you were suggesting they might do something wrong, which is a bad place to start when you want to gain agreement.
Being gentle with your reasoning might sound a bit touchy-feely, but as a researcher you should already be aware that people’s feelings make a big difference in how they respond. Try reframing the consent form as fulfilling many purposes and see if that helps.
Good luck, and thank you for remembering to use the informed consent process!