Why aren't snakes on top of foodchain?

Guns.

Humans are only on top of foodchain because of weapons and intelligence we posses. But I don't see you or me, winning against 10m Python that won against Alligator whose bite is 10.000 pounds per inch.

First of all, which animal is on the top of the food chain is a subjective matter. For a certain ecosystem, being at the top of the food chain means that you are not a food source for any other specie. That said, human is certainly not the only specie that is considered to be at the top of the food chain. For example, at a forest, a bear and an owl might be at the top of the food chain. In this case, it doesn't make much sense to compare the bear and the owl as to who is on the top of the chain, since no one eats each other. For the same reason, it might not always make sense to compare humans with certain non-edible species of snakes as to who is on the top.

The fact that a speice (e.g. human) is  on top of the food chain does not mean that it is invulnerable, or that it is the strongest and will never get eaten by anything. It just means that, it generally is not a food source for any animal (e.g. no animals eat humans often). The reason that humans do not get eaten often is our intelligence and technology. For another specie the reason might be another (for example a poisonous fish that is not edible might be considered to be at the top of the food chain because it is not getting eaten)

If we lived somewhere without technology and weapons, we might were a great food source for animals like lions, bears etc. but it's because we posses this technology that we do not get eaten often.

That sums it up.

Snakes are missing their trigger fingers

^ Precisely

Resolved.

In the Florida Everglades they are, eating deer, rabbits, raccoons, possums, and right now all humans can try to do is contain them. Emphasis on try.
Right now, they are clearly not on top, but in the Everglades they are, because they were introduced for hunting a long time ago, and the population grew too large and the other wild animals had no idea how to adapt to this new creature.
Hopefully we can control them. We, afterall, have guns.