I believe your way of thinking is based on the wrong assumptions: Others will make mistakes.

Raising is primarily a healer's job. It's very likely either healer will also have Swift Cast ready to raise. If that is the case, yours is wasted or you're wasting a healer's Swift Cast. If one healer dies, why wouldn't the other healer have Swift Cast ready to raise said player? If both healers are dead, it's not very likely your swift cast raise will save the raid.

Additionally: Consider the summoner's position on the DPS market right now, especially in FCOB. You can't afford to waste mp to raise anyone and you need to squeeze out every single point of damage you can if you want to keep up