Given the sheer amount of data on Reddit, this is really not feasible nor scalable, nor is a long term solution. A simple CloudFlare configuration will quickly put an end to such a solution.
RSS exists, however only allows you to subscribe to subreddit posts, not comments.
This is why the API changes are such a big deal.
If you pay to add a feature to a product that was previously not available, sure, that makes sense. But in this case, at the point of the transaction, and they hand over the keys, the ownership of the product is now 100% transferred to the customer. They should and can do whatever they want with their property. A manufacturer equipping a feature because it's cheaper is frankly not the customer's problem.
Imagine buying a house but you only get access to certain rooms. They set the price, the customer just pays for it. If they want to cover the cost of adding the heated seats feature, then add it to the starting price.