I'm a very good HBK pilot who knows how to run the Mech, although I appreciate your effort to educate me.
What I was driving at, is that you often find yourself in a less-than-ideal situation. When that happens, being able to hit someone at 500 meters, and deal damage, is very advantageous when you are seeking to close, find better cover, etc. Now that the Brawler HBK's range will be reduced so drastically, it will be regulated to hunkering with its head-down until the end of the match when the enemy team pushes forward to roll the HBK's team, or when there are few enough Mechs for it to come out of cover without getting ripped asunder by PPCs, Gauss, LL's, LRMs, etc.
I have multiple HBKs with a variety of builds. Some are being buffed by this patch, like my 4P. Some are getting buffed and nerfed simultaneously like my GI and 4H. My overall contention is that the AC/20-packing HBKs are already at enough of a disadvantage that they don't need this nerf. The AC/20 forces them to sacrifice substantial speed to pack the weapon, so they can't close quickly if caught in the open (that is one of the counters to the brawler HBK - outmaneuver and shred it before it can close to range).
What I predict, is an exodus from the AC/20 HBK Brawler field and more AC/5 builds if people keep their 4G's and 4H's. Otherwise, we will see them start to vanish until only the other variants are often seen.
...I heard about you - you're whining is legendary! Haven't had the misfortune to drop in game with you yet (fortunately!) though.
Just fyi, since you clearly don't know much about MechWarrior: The ability to boat and build whatever you want on your Mech is a cornerstone to the game since it's inception. The MechWarrior game series has always had this in it (haven't played TT, so I can't speak for it). Furthermore, canonically, the books often featured boats and pop-tarters.
Learn to deal with it. Sure, it's no fun to get rained on by an LRM boat, but that probably means you weren't using cover effectively. Sure, it's no fun to get boomed by a Boom Jager, but that probably means you weren't cognizant of your surroundings, or you charged down his throat. PPC and Gauss snipers are difficult to counter, but again, proper use of cover can foil them until you can close to range.
Each Mech build has its own advantages and disadvantages. Simply because you are not good at reading the sensor data to determine those factors and then decide how to fight that enemy does not mean that the game should be bent out of whack into something unrecognizable.
Non-UAC's jam? No way!
Increase the tonnage per JJ? Doesn't make any sort of logical sense...
Lights boating lasers? Well, they're too light to fit AC/20's (except that one Raven...) so you should be thankful!
9 ML HBK? Sure, but he has to deal with the heat load and be able to pilot effectively - there are downsides!
Alpha as last ditch effort? Sure, but a good pilot can also use it as a starter to drive a wedge into enemy armor - learn to use it yourself.
Decrease damage and add armor? Not canonical bud - get used to it. You can't take over a dozen years of precedent (game-wise, not counting the books) and turn it on its head.
Max of 2 MPL fired before Ghost Heat? That's already in the game bud.
1 LL...PPC...Double heat? Also in-game already.
LRM chainfire...etc. Not canonical and really ridiculous. I can't stand LRM boaters but, love 'em or hate 'em, your demand is really unreasonable!
MGs are good as they are - buy the range extension module if you need extra (I did - it was worth it!)