At least they gave a lore reason.
masseffect.wikia.com
Pointless retcons in Vyda games
Asher Russell
Nathan Phillips
It's magazi– oh fuck it. Fuck Bioware and fuck Mass Effect.
Caleb Reed
A reason that's fucking retarded both in universe and without.
Jace Perry
a half-baked excuse, you mean.
Kevin Bell
What you mean?
Logan Brown
If I remember correctly the biggest flaw in their excuse is that the guns were useless without a thermal clip. Why wouldn't the guns just revert back to how they worked in ME1 once you were down to your final thermal clip, it didn't make sense.
Brandon Rodriguez
Lazyness I guess. It'd been neat if you could fire the weapons on a really slow rate without thermal clips but they were too lazy to bother and just amde a standar ammo system
They acknowledged this shit mistake on me3 and added a rifle on a dlc that works like me1 weapons, and it's also absolutely broken
Bentley Morales
Beretta > Glock tbh
Gavin Bennett
It's fucking retarded that any military force would ever, ever, switch from a system that didn't require ammunition to one that does. The fact that the entire universe switched over to this inferior system over the course of two years is equally as retarded.
By eliminating the need for ammunition you eliminate dozens of concerns surrounding military operations. Weight is cut down, your soldiers have more space, you cut down on costs, and most importantly they can keep fighting with those firearms fucking forever because they don't run out of shit to shoot out the barrel.
Including them meant that everybody in the ME universe suddenly got ten times more retarded between games.
Ayden Howard
Mp5's make people think of SWAT or intelligence agencies, usually the good guys and civilians
M4 is what everyone thinks of when they hear "military rifle" now ask yourself, why would they make this change? I mean other then not being a /k/ fetishist.
Same thing with the beretta and the Glock, Beretta is good guys, Glock is shady govment