I would have to respectfully disagree though. Cos like I said, the reason why free trial is there in the first place is to entice users. There are so many products without free trials.
Again, the burden should not be in the shoulders of the end user. There is no reason for the company to ask for credit card other than data sharing, other dark patterns and spam. Like many have mentioned, spam can be dealt with better by other means. These are companies who have tried it out. I don't know what else more to say. :)
this risk will always be present. Choosing a well known processor will reduce it quite a bit imho.
If you're asking why a user would take on this risk, i would say that they are getting a "free" trial in return. By having to take on this risk, the user is more conscious of using the product, and cut out the people who would just kick the tyres.