Is the Mormon baptism by proxy practice much different from infant baptism?

[Insula Dei]

I think the difference is that the one thing involves parents making a choice on behalf of their child (, which they do all the time), whereas the other involves people doing something against the clear wish of someone whois capable of having desires of their own. A better analogy would be having catholic last rites performed on your atheist father, who no longer is capable of expressing his opposition. That clearly is both seriously not okay, and useless.