Well, there are two sides of the coin actually. First one is that those weapons aren't really common, they're still exotic due to their nature, thus limited use and shouldn't really be more common than regular human weapons on player ships. Personally I don't think that's a big problem, however excess of said weapons kills the identity of the ships. Unlike situation with Supernova, that is hopefully to be fixed with Clayph's SN project, Blasters and Cannons aren't the only weapons of their class and usage available, so they aren't comparable to SNs in this context.
As far as historical part goes they were initially seen on Liberty ships during mission where Edison Trent and Co. ran to save president Jacobi from the clutches of Nomads and corrupted/infested Liberty government. That's when you see adapted weapons for the first time, they're even called prototypes. They are adapted for the use with human ships, that is true, but the timing suggests they originated and/or somehow in a certain capacity were developed by the Nomads for use on the infested pilot's ships to give them arms superiority, as seen by massive damage they dealt, in same fashion they equipped Rheinland fleet with cloaking devices that are, once again, are courtesy of our blue skinned friends out there.
As for the future of Blasters/Cannons - I think they will remain as they are, but certain changes will happen to make it more plausible in terms of roleplay. There is a work going on in that area, once everything will be ready and confirmed I'll explain details of the changes.
