Thing is, in the 3025 book, where the original 1A1 was first published, it was faster than most heavies, and rivaled some of the mediums for firepower. Any mech fast enough to intercept one, was also, usually, fragile enough that it didn't want to be on the receiving end of a charge from the Charger.
Meanwhile, it's a durable 80 ton design, with nothing that explodes, in it. By itself, it's an inferior design... but when considered as part of a team, especially in the era of single heatsinks and average 4 gunners, and it can actually do it's job of scouting and bringing data home. Anyone that is fast enough to intercept it, is going to try and stay at least 10 or more away, to pick it apart, and avoid physicals.... which means medium or longer range, on something that can generate a +3 mod, running flat out.
When you give it some support, and let it just do the job of getting data, it really can be a solid member of a lance. It can also bodyguard fire support designs, because anything getting back there, to mess with with your long range stuff, probably doesn't want to be on the receiving end of an 80 ton tackler looking to make personal fouls.
Nahuris