Given that emplacements can not move, they are very vulnerable to thought out strategical counters. You can say that it takes little micro or skill to have an emplacement locking a portion of the map down, but the skill and micro comes in defending from a well executed attack on an emplacement.
Come on! In an average level 3v3 or 4v4 game (i.e where emplacements currently get spammed; not high level play, but a specific target of this patch), it is SO easy to defend a sim city against the average opponent.
Royal Engineer Regiment commander for 'Stand Fast' auto-repair to ALL of your emplacements at once for just 50 muni. That in itself pretty much negates the majority of damage from two mortars firing at it for a long period of time, and with a minimal level of micro your mortar pits will shred enemy mortars, or at least force a retreat which will ensure on their return your emplacements will be at full health.
Once 'Stand Fast' is on cool-down, brace can be used for 30 seconds of invulnerability in which you might risk manual repair with a couple of engies.
Even if they manage to take out one pit, you will have been doing huge amounts of damage to them, and the replacement 400mp is absolutely nothing in larger team modes, and will be built in 15 seconds with the couple of engies you almost certainly will have waiting next to your emplacements.
Of course players of a higher standard will be able to effectively and efficiently counter, or those who are communicating to co-ordinate actions, but any 'average' player won't be removing that sim city without later game LeFH spam or OKW offmaps. Even then the Brit player will have the floated resources to switch into Comets and Fireflies, knowing that the opponent has tied up most of their pop cap into specific arty counters to sim city.
Again, this is not high level play, but this is what is going on in the 'average' 3v3 and 4v4. You will see plenty of people in ELO rank 15-20 in these modes successfully crutching on emplacement spam / auto-repair as the backbone the rest of the team build from.