First of lets debunk these statements...
Yes, bounty hunters have a smaller arsenal of guns to chose from. However, every gun they possess is illegal and cannot be used without being charged and seized. Bounty hunters have access to legal armored vehicles and primarily the ability to restrain and keep a person for a maximum of 10 minutes and utilize blindfolds for a simple 1.5k charge. That is some true power.
Bounty hunter has access to the exact same clothes and armor as the rebels do (Might be exceptions at this time, report if known). The point of rebel is to have very big guns. Things like LMGs, 7.62 weapons and armed vehicles are the draw of being a rebel. They are not government sanctioned like bounty hunter is.
There are plenty of bounty hunters who operate with the fully legal equipment and do just fine. Is it more of a challenge? Why of course it is, that is why it is encouraged to pick your battles and work in teams of bounty hunters. To say that all BH guns are ineffective is simply wrong. Are you able to tap out orcas and ifrits like MKs can? No and that is by design as bounty hunters are design to be a threat to rebels not a complete demolisher of every persons fun.
You have to give cops a reason to search you. Here is the list incase you have not read this portion of the guide book: Link. Just because you have to think more around the cops, does not mean you should be handed the keys to the kingdom for abusing this. I must also add if you read the popups from when you gain your bounty hunter license, the intent is for you to work in the absence of officers. I must also add that while you may have good intentions as a bounty hunter, other before you have made the owners of the server make this change happen. I know I have heard of many stories of people abusing these weapons on civilians who suffered the most when these guns were legal as the repercussions were so minimal. I state this to give you a better picture as to why these guns were moved to be illegal and not to rub out all of bounty hunting.