Left to their own devices, history tells us that corporations take advantage of workers whenever they get the chance in order to bolster their profits. There may be individual companies that act differently, but this is the overall culture and workers need unions to protect them from greedy people at the top.
Fast food workers should unionize. The industry is known for not treating workers well, with poor working conditions and low pay. This is represented by the latest news that nearly 10,000 workers are suing Chipotle for unpaid wages. If the workers were to form a union. it would raise the pay and provide benefits.
Fast food workers should not unionize, because doing so would eliminate their jobs. Fast food jobs are entry level, low-wage type employment. Furthermore, automation is making it possible for restaurants to eliminate workers that take orders, because a computer can now do this. Therefore, if fast food workers unionize, it will only speed up the automation process.
No, fast food workers should not unionize, because fast food workers see too little in paychecks as it is. If they unionized, they would have to pay a large percent of their pay to the unions, rather than keeping it. As it is, fast food companies can't continue to pay workers more and more, because that only results in raised food prices, and then less people will get fast food. It's a vicious cycle that will ultimately put them all out of business.