Now you have.
I suspect that there were probably one too many accidents, otherwise I don't see why immersion couldn't continue as it had/has in the rest of the Church.
I have never heard of infants drowning in baptism in the Byzantine tradition.
Unfortunately, accidents happen. Thankfully, they are exceedingly rare.
Does it have to do with the way the infants are plunged in? In the baptisms I've seen the infants are sort of quickly "scooped" through the water in one fluid motion without pause. I really don't know much about this stuff...
I've seen different methods of immersion within the same EO jurisdiction, so I suppose it depends on who trained the priest. I've seen veteran priests immerse babies thrice but without the head ever getting wet, and I've seen newer priests do standard immersions. I've seen some immerse with the method you seem to describe (even done cross-wise); one time it looked so violent I wasn't surprised at the vehemence with which the child screamed for the rest of the service. There doesn't seem to be one way to do it.
In our tradition, on the other hand, there is very much a standard way to do it, and much of this is due to the symbolic meaning of the rituals. For instance, the child faces East while the priest faces West in order to baptise him. The priest keeps his right hand on the child's head and uses the left hand to pour. This is the exact opposite of what you would expect (right hand to pour, left hand imposed on head), but it's because the priest is facing West and not East: inverting the movements allows for the Cross to be signed from East to West to North to South, whereas the priest doing it as he is accustomed would make an upside down cross (West to East to South to North). In a similar way, the other rituals are highly symbolic, and changing them pretty much changes their meaning. I suspect that changing the method of how the washing occurs within the rite was deemed more appropriate than changing the rite itself to accommodate one particular method of washing.
Also, why do Indians like to put those tacky Christmas lights in their churches?
Seriously, I'm not sure. Tacky Christmas lights seems to be a pretty universal form of adorning churches throughout many parts of the old world. It's actually a practice that unites EO and OO. I'm not too keen on tacky, but I live with it when I encounter it.
A veteran OCA priest once spoke to me about "tacky lights" in at least one of his former parishes. His explanation was that when it became possible to decorate churches with electric lights in this way, the people didn't consider it to be "tacky" but a "worthy offering" befitting the sanctuary. Standards change.