Generally speaking, the defensive options tend to be more team-friendly than the offensive option, last longer, and, for the most part, affect all the players on the team. On the other hand, the offensive options are generally area of effect (AoE), only having an affect on one area for a very limited amount of time. However, in cases where there is a vehicle involved, such as the M3A3 Bradley, or where there are embedded enemies, it may be more worth the points to use an offensive action.
Strategically speaking Defensive support chains guarantee points vs Offensive chains offer the potential for greater points. Take Intel VS Mortar Strike. Intel gets 25 additional score chain points on activation. For a Mortar Strike to be points effective you'd need at least 2 kills as a Tier 1. (10x2 plus 5 x 2 = 30pts plus potential for savior/revenge/defensive/offensive/vehicle damage point bonuses. Instead of immediately activating that Mortar Strike and getting nothing you may want to hold it until you get to 75 points, activating the Intel and immediately scorechain into a Match Ammo or Rocket Strike.
Do NOT immediately activate that scorechain bonus. If you get 50 points and zip off that Intel then get killed, your team has UAV but you are back to zero with no bonus. Try this: get 50 points and WAIT until you have 75 points then Activate Intel and immediate scorechain up to 100 points (Q.E.D.) If you die in the meantime you will respawn with Intel VS Mortar Strike in hand so you'll only need to get 25 points then activate your Intel and chain up to Intel VS Mortar Strike again.