Topic: What is it with AC/5s and SRMs/LRMs on everything?
Reply: What is it with Medium Lasers and PPCs on everything?
Other than MLs and PPCs, everything else in 3025 was ACs and LRMs/SRMs because there really wasn't much else, and the weight of an AC/10 or AC/20 prohibited their use on a lot of medium-tonnage stuff, even after they were added. There are a few "niche" AC/2 wielders, and a fair number of designs with MGs, plus the occasional "incendiary" design with a Flamer. That's about it.