But the pods would be effective in that you could drop them from the ship at high velocity and pack a good amount of combat gear into them without having to slow down or circumvent some anti-beaming technology.
I sort of doubt the goal would be to drop individual infantrymen in full gear; after all, the pod interior is cramped and can probably only accommodate a "shirtsleeves" operator.
It apparently had enough room (in addition to Kirk) for a jacket, a tricorder and some survival gear. In a combat situation it wouldn't carry much more than that, with the inclusion of a phaser rifle and perhaps a couple of photon grenades.
Shuttles would flexibly haul down infantrymen and their gear for disembarkation on a battlefield or next to one
And when shuttles are feasible for that sort of operation they would probably be deployed. But even in Star Trek there are situations where paratroopers are preferable to air cavalry, and in this case there are situations where a simple space jump isn't possible. Much like the ODSTs from the Haloverse, it's a special tool for a special kind of job.
Trying to use any of these technologies to deliver troops under fire would probably be as dangerous as any opposed amphibious landing today.
Way MORE dangerous, actually. They don't call them "Helljumpers" for nothing. But again, these would be the delivery system of choice for, say, quickly inserting a strike team to eliminate transporter scramblers or ground defenses capable of interfering with shuttles and/or transporters. In those situations, drop pods would be small enough and fast enough to power dive into ANY landing zone, no matter how hot, and quickly turn it into a nice cool beachhead.
The craft themselves would stand no chance unless other assets performed defense suppression; it wouldn't be worth the while to put too much effort into making the craft better penetrators.
Considering the difficulties we've seen throughout trek history--even in the Abramsverse--in intercepting small fast-moving targets, I don't see that as being a problem. And especially if you're launching them on ballistic trajectories, they'd have a far greater chance of making the trip than a shuttlecraft.
Examples form TNG come to mind where they would have come in rather useful; "Darmok" being one example, in the case that the Enterprise wants to send someone to help Captain Picard but the Tamarians keep shooting at their shuttles. Without warning, Enterprise fires two dozen drop pods carrying security teams and pattern enhancers, several of which are decoys to give the Tamarians something else to shoot at. Law of averages, SOME of these pods will inevitably get through, the security teams will be able to link up with Picard, deploy the pattern enhancers and beam him the hell out of there.
Given the possibility that the drop pods can be deployed without dropping the shields (torpedoes can, so why the hell not?), then an even better example might be in Arena, where Kirk reports the outpost has been destroyed and the Gorn begin to attack the ship. If the situation were only slightly different--if, say, the outpost was still somewhat intact with a large group of survivors fighting a desperate holding action under Gorn seige--then Enterprise would have to drop several of those pods with reinforcements and additional supplies to reinforce the ground teams without taking the risk of lowering its screens (especially in the Abramsverse, where matter transport can take between six and ten seconds).
