what makes these people in the parking lots more important tha other people who are using the roads ?
They are
equally important. But for whatever reason under certain conditions, the traffic flow does not allow the vehicles in the parking lot to get in or out at any reasonable rate. Consequently ... someone is needed to direct traffic.
the company that hires these cops might want to change the way their parking lot is setup.
Sure, but that takes time and costs money. In some cases, for 99% of the year, there is no problem with traffic flow, but special events overwhelm the normal traffic controls from time to time. In these situations, it may be better to NOT build a new traffic signal, but just hire someone to direct traffic when there is a special event. Other times, a certain traffic flow is anticipated and the sign / signal arrangement is designed according to that, but the traffic flow increases beyond what the arrangement was designed for.
Why can cops be rented out anyways ? do they carry their weapons ? i know they use police cars, which shouldnt be allowed.
Why not?
This thread exists ... which implies that there are people out there who are inclined to disobey people directing traffic (and thus risk causing a collision by doing so).
If the person directing traffic is a cop ... they most certainly carry all of the legal authority that they normally do. And ... as a driver, you have to follow their instructions. Take note of section 134 of the Highway Traffic Act.
Drivers who don't follow directions need a cop present to ensure that they follow directions ... or they get a ticket. THAT is why the cops are available to hire for those special occasions. THAT is why there is frequently a cop present at a construction site where special traffic conditions exist on account of the construction work. And why shouldn't the cops be available to hire for those situations? If they weren't there, and people got used to disregarding the construction workers because they don't have legal authority, there would be no effective traffic control, and that would be unsafe for everyone involved.
Of course, it would be a whole lot better if people FOLLOWED INSTRUCTIONS, so that the construction site wouldn't have to hire the cops ... but some people are not good at following instructions unless there is a threat of a ticket if they don't!