Because it's a war zone. The Kiosks are often laying sideways or otherwise looking like they were quickly deployed there.
Also note that several of them have POLICE clearly written on the side! They were likely dropped to help with riot and evacuation control, and now the Corporate Mercs are taking simply advantage of their presence.
All the bodybags in the civilian areas. Likewise one has what looks like a destroyed quarantine tent, implying it wasn't the fighting that killed those people in the bags.
J. Vansaint “Viper” secondary skin is named Patient Zero and shows his right arm exposed and sickly grey, implying him being infected by the backstory Sentient Insanity Virus (SIV). The skin's name implies he might be one of the very first infected. However unlike regular S.I.Vs he is completely sentient and works as mercenary. This either means he is a carrier and or has developed an immunity to the virus. Both making him ideal to fight in the infection centers.