I think the arguments against Net Neutrality are more based on fear/uncertainty than facts. People are scared WHAT IF ISPs are going to charge more for certain services, block or throttle the websites of competitors. I think there are ups and downs of Net Neutrality, but most of the websites don't bother to discuss the downs, but more focus on ups.
When ISPs are going to charge less for specific services, let's say like facebook? because facebook keeps paying them a decent amount of money for a decent bandwidth allocation, it will help certain people to purchase facebook only packages from ISPs, so they don't have to spend more money for other services like google plus, instagram. It's like how you could purchase a cheap iPhone from a network carrier, which is locked to the specific carrier's network. Someone can argue ISPs are not going to reduce the prices, but if it's not reduced it's hard to expect facebook is going to pay for ISPs, after all what is the point of paying when ISPs don't give any benefit to customers in return? So I believe there will be website oriented packages from every ISP at a cheap price like facebook package, whatsapp package, google plus package. This is more beneficial to poor/middle class people because they can use specific services at a cheap price. Also some businesses can come with agreements with ISPs to release packages which grant users to access it only. This is beneficial to certain people like farmers, educators, students. Farmers can access a limited set of websites which educate them with latest techs, and all other information, educators can access to websites like wikipedia, stackoverflow which are useful when learning things, students can access a set of websites consist of educational materials and made up by ISPs, I believe it will be advertised as student only package like how github is giving away discounts to certain services. This is more beneficial to children more than adults. Parents can buy their children a student package knowing they won't be a prey of an online predator. It's true, we can still build our own network which blocks all unnecessary websites, but not many people are able to do it.
The disadvantage of this is it will allow corporate level websites like facebook, netflix, google plus to thrive without much resistant. It's also harmful to small businesses, bloggers because the audience to their websites are now much lower than used to be, for example facebook is often used by small businesses to promote their contents, if ISPs started giving away Facebook only packages, advertising on social networking will be a huge waste of time, because so many people won't be able to access to your third party links, meaning you are forced to post everything in facebook, which is on the other hand beneficial to facebook because less people are leaving their platform. Also when small businesses realized, there is no use of posting links to their websites, they will start dumping their websites in favor of facebook, so I assume then facebook will create a separate service like medium for posting blog articles. So slowly, this will grant more power, and control for big websites. Having your own website with a decent traffic will be the history.
Some people argue that this will increase the competition among ISPs, meaning when big ISPs are going to throttle bandwidth of certain small websites, it will effectively create a market for small ISPs to target them, but this is not that easy. First it's so expensive to build infrastructure, and it will take years or decades to cover certain areas, especially rural areas. It's like how people are still forced to buy Nvidia/AMD graphics card at a higher price tag. They seem like cheaper for some countries, but still graphics cards are overall are expensive due to the lack of competition. There are no competitors in the market, because it's insanely expensive to build infrastructure to build the graphics cards. Even Intel is still unable to compete with higher end graphics cards of both these companies. In a nutshell, Net Neutrality has a lot of benefits, but it also has some down sides too.
If you are a regular user who just wants to see things, then Net Neutrality doesn't do much for you, because you can always purchase facebook only package at a cheap price and read news posted there, and use it. But if you are a small business owner, or a blogger then Net Neutrality is a disaster, because it hinders the growth of these entities.