Good watch, could watch again, and can recommend, especially for a bad movie night.
For such a horrible premise, this actually holds up pretty well. It's a bad movie, but it's still pretty entertaining. The snakes almost have the same behavior / pacing as a "blob", slowly seeping through the plane and over taking people bit by bit.
Without a veteran actors like Samuel L. Jackson or Kenan Thompson to hold things together this could have easily fallen apart in a much worse way.
The "realism" is certainly not a concern. While pheromones are a thing that can incite some behaviors, snakes aren't loyal to each other, especially different species. Once you accept the initial scenario, every ridiculous thing that happens is funny, and the tension is up just because you have no idea where the snakes are coming from at any time, and the knowledge that the entire setting could just fall out of the sky, even if enough people survive the snakes it could all end with a crash.
There is likely a truly good version of this movie we could get, but for now, making fun of this one should be a good time.