I have seen this argument, that people are gonna use long pipe lines instead of trains. And I think that might be true to some degree in the start of the game. But, you're already going to expand your rail network anyway, because you need it for ores. And when you already have it, you might aswell put all liquid stuff on the train aswell. So I don't think it's going to be a "problem".

And your last point, in a biter world I don't think long pipelines are going to become a thing at all. Because losing a pipe is just annoying if it's out of your roboport reach. Maybe peaceful it'll be usefull, who knows.

But iam sure somebody is going to make a mod that reverts it to the old system, long live mods haha