Solving this problem is very hard. You first need to prepare and fix some mechanics before you can chance the motivation. Yes, it is the motivation, I see a lot of people leaving games if they see >= 3 ppl from one corp. A couple just afk in the MCC, because GÇ£itGÇÖs not worth trying against themGÇ¥.

I see two major problems which need to be solved.

Problem number one: Guiding/Leading the herd.
In the most games more than half of the people are not in the squad. I think it would be great if randoms could get a fast join possibility like you see it in BF3. If you have a squad open, and you donGÇÖt lock it, this people can join you, and if there are leftovers, a new squad will be created. Now that you have the herd, you need to guide it. And the spin wheel squad commando menu=SQM is not a validate tool for this. We need something faster, and of course bug free. Things like: increasing the distance between the panels (in the SQM), adding new options, like showing a path or way to go, increasing the highlighting speed, by maybe highlight the enemies for the squad to see who is the squad / squad leader shooting right now are just a few possibilities. Guiding this herd is one problem.

Problem number two: Motivation.
People need to see why it is worth killing a proto, CCP could accomplish that by showing at the end of the game more statistics, like GÇ£who killed the most expensive cloneGÇ¥, GÇ£how much ISK are destroyedGÇ¥, maybe even have a minimal chance to get the salvage loot from a killed enemy (not all the fit, just leftovers). The people must feel the need to join a squad. This could be accomplished via more WP, by more I mean: WP for spotting and scanning enemies and killing the highlighted (this should be the one highlighted via member via shooting at him, and not via the SQM) enemy. This are just examples, but this way even a sniper would feel the need to join a squad.

Now, I think this to things should be fixed, and you will see random groups rise against corp squads.