Like I say, no attrition. Most of these horde missions that actually meet equal resistance take casualties in numbers that make Black Thursday look like a milk-run.
Well, there is attrition of sorts, just not in the traditional sense. Time and Energy, on the very grand level, are the ways attrition can be seen here.
In general the defender has two things going for them: closer to resupply (of aircraft, from the base--though cv battles are often different), and the complete horde mentality of the attacker which is completely energy-ineffecient. Although the attacker has the option of starting the assault energy-rich, undisciplined tactics and complete lack of strategy have the effect of completely robbing the attacker of this energy in short order.
To combat this, the attacker needs to use some actual teamwork. Though they claim to, this is often a delusion or outright lie.
Teams are disciplined. Teams have tactics. Teams have a strategy.
What we see in the MA is no team; it is a mob.
When was the last time you saw a mission launch that had different but mutually supporting targets? When was the last time you saw a detachment of Mustangs 50 miles away preventing reinforcements while certain elements concentrate solely on the town, others on the VH, a few on vulching, and more on high cover?
It doesn't happen. What you see is one mass of aircraft, all loaded to the gills with all the ordinance they can carry, all headed to the same base, from the same direction, at the same alt, and then all blowing whatever alt they have to chase after anything low and red.
Strategy? Please. Teamwork? Hardly. Mob rule and weight of numbers are the only things they know. Really, many base takers remind me of the kid scouring the internet for cheat codes because they can't figure out how to beat a level, or even the guy at the local hockey rink playing in the lowest division so he can be a "star."
I don't have a problem with people taking bases, or doing anything else that's generally frowned on by furballers. What I have a problem with is people putting in absolutely no effort, and expecting anything other than contempt.