>>23467415 (OP)
They'd be shit which is why mobile suits as a concept just don't work.
>2 arms 2 legs
If arms and legs are SOOOOO good for zero-g construction, why not just build a giant mechanical centipede with 10 arms and 10 legs?
>Piloted by one person
This means you can only do one thing at a time, and that thing is imitating a human's range of motion with giant pieces of steel, glass, etc. You need 2 mobile suits to do the job of two people, instead of having one purpose-made ship to do the same job as 20 people.
>humanoid shape
Means you can't have a mobile suit do the job of a crane, a bulldozer, a shovel, a compacter, a cement truck, a skyscraper lift... You force your construction crews to work as if they are humans in space suits. It's stupid and inefficient.