As a cybertech, I am having a hell of a time getting fiber-mesh from missions (as an inq in his mid 30's). I think on average I get 2-3, as often it's bundled with another mat. I am always really low, and send my guys out as often as I can afford it. It's a green mat, so I'm having a hard time understanding why its so rare.
Perspective probably has an impact on my current frustration, but it is quite expensive to run as many missions as I do.
A couple patches ago, the drop rate from scavenging mobs (droids) was nerfed, and I don't mind that at all. However, I do think the high tier (highest that can be cc'ed, not sure what they are called), should be higher than 1-2. It's a challenge to clip them, and even a greater challenge to get a pug w/o a scav tank ( or a group that still relies on healers to top them off in between pulls) to get them to hold pulling for 2 seconds so I can grab mats.
I'm not sure what the amount should be, maybe 2-3? 2-4?