There's a lot of factors that contribute to energy weapons being ass. Small map size and low view distance are two of the biggest, but I can at least see why the maps are setup the way they are. Unless they doubled the maps in size they can't extend sensor/view range or you'd start almost every deployment already in combat, which means shit takes even longer and potentially gets way, way harder with how frequently they have you square off outnumbered 2:1 or worse. Extended map sizes also just means much longer missions, and brings potential performance problems in a game that already runs like ass, so I can at least understand the range thing.
The shit I don't get is changing out missiles work at their core. LRM/SRM racks always had huge damage
potential, but the odds of you landing 20 missiles out of an LRM rack were damn near 0. All missile weapons had an "amount" roll basically off 2d6 that determined how many missiles connected, and that was even after you made a successful hit roll. I think a 7 on the roll was 50% of your rack connecting, and 12 was the full rack? I forget the exact numbers, but the point is not only did you have to pass a hit roll, even then you weren't getting 80 damage out of an LRM20 in most cases. So in this, not only is the amount roll gone, each missile has individual hit rolls, which makes it incredibly likely that you're getting like 18+ missiles out of every LRM20 to connect. Combine this with how the precision strike morale thing allows you to focus like 80% of your LRMs in to center torso or whatever and of course energy weapons are going to start looking like shit.
There's also no AMS in this tech timeline, so you just have to eat it with no real recourse. Put the amount roll back in for missile systems and heavily nerf or remove precision strike and suddenly PPCs/LL/AC5s all start to look far more attractive as effective ways of dealing targeted damage at long ranges.
Edit: found a pdf of the old master tables. Look at the missile hits table at the bottom of page 2. That just doesn't exist here and is why missiles are so fucking OP
http://www.pryderockindustries.com/downloads/gameaids/tables_bt_bmrr_tw_grey.pdf