Kids just don't understand opportunity cost. They just see it as pure profit since they farmed the materials themselves. I can craft the kits but still end up just buying them off the gtn when I need them.
It would be interesting to see analysis determining how much 'profit' difference exists between selling the mats and selling the crafted the items, along with the true profit potential over a given time period (credits per hour) assuming a full crew of companions available.
Though for that analysis to be worthwhile it would need to factor in crits and the RE returned mats to come up with an accurate 'cost' for making an MK-6 along with accounting for the crew time required to craft the items (which could be used to run missions for more mats).
And the post right above me shows exactly what Frostbyt was saying with people believing the cost of mats are zero because they picked them up off the ground.
It doesn't matter if you gathered your mats or spent 1,000 credits running a mission to acquire them, if the mats sell for 2,000 credits and the item you craft sells for 1,500 credits, you will be forgoing 500 credits by crafting (and this is before factoring in the lost crew time spent crafting the item).