I don't think you guys are taking into consideration on what they are using their pips for.
An engineer can sit there an buff ppl up with kevlars and ammo upgrades but then he has nothing for turret setups and mine traps. Soldiers have to balance the use of grenades, flashbangs and your ammo at the same time. If they are attacking, I'm sure a soldier is not thinking of your ammo levels.
The other problem is that you don't see if they are out of pip. I think the game needs an indicator so that people know if someone can't hook you up.
Oh and when I play as a soldier it's harder for me to see who needs ammo. It's not like the medic that has an obvious health bar, you get some bullets but that is not an good indicator of how much ammo you have left unless you have less than half I guess.
Remember just because you don't see them playing how you expect them to means they are not playing their class correctly.
I account for all these things and don't generally worry about buffs too much. I hope for a weapon buff as I run, but it's not the end of the world if I don't get one. I would rather have the turret defending my ass, or a mine blocking the flanking route, and then once those are set the Engi can worry about buffing if he's well off enough to do so.
Medics have a lot of pips, but shouldn't be buffing in the spawn (unless it's the sprint, or maybe metabolism) because the health buff is a much more effective buff once you are in battle, as it instantly refills your health and gives you a little extra, but of course the idea of getting your buffs before entering battle is more appealing to R&G type players, or those that separate from their team after leaving spawn. This is where communication comes in handy. "Hey, I'm going to flank them, can I get my buffs now?"
I don't want more indicators though, there's too much crap on my screen already.
For those who want more buff, the easiest way is to get a mic and ask, or show your worth to another player and they might choose to stick with you and keep you running.