Laser vomit works because it can put up a fight at any range. It usually isn't
optimal at any one particular bracket, but it can perform each bracket decently. In other words, it's a jack of all trades type of loadout. It can respond to changing conditions better than a niche-specialist can.
For example, a short range specialist has high effectiveness in short range, but zero effectiveness at long range. Long range specialists are highly effective at long range, but often become weaker in short range. Laser vomit has moderate effectiveness at every range. You get to be really good at X and really bad at Y, or you get to be decent at both X and Y.
Laser vomit is versatile. Laser vomit is always effective, never not effective.
There are also other factors in here, such as upfront tonnage opportunity costs. Lasers are more tonnage-efficient than any other weapon family. They require vastly lower sacrifices than ballistics and some missiles, which makes them more accessible to a wider variety of mechs (many mechs run out of tonnage real fast).
There are also nerfs to non-laser systems that have contributed. Specifically, Autocannon and PPC velocity nerfs have distinguished lasers as being much more accurate at long ranges than ACs. An honorable mention is the Gauss Rifle, which is a very excellent weapon mainly because of having so damn much velocity. People say "but low velocity isn't an issue, just lead/aim better you nub," but the PPC velocity nerfs have proven this argument to be wrong by going from dominant to mediocre with just a velocity nerf. Lasers, being hitscan, are very easy to hit with at long ranges, even if just for partial damage.
The Mad Cat and Ryoken have exasperated the situation somewhat with their large engines. These two mechs have forced IS mechs to either use a STD engine to survive their laser alphas, or use a very large XL engine to not lose the mobility contest. In both cases, those engines eat up a lot of tonnage. Lasers, conveniently, require relatively little tonnage, which makes them the optimal choice for large-engine builds.
Clan lasers in general have also contributed by just being so damn amazing.
Edited by FupDup, 22 May 2015 - 11:53 AM.