Sure, you would certainly think so. Of course, neither of us are railroad executives (I assume), so while we may think that in an ideal world things would be done a certain way, (and while we might wisely agree and nod our heads and stroke our proverbial beards while doing so,) that doesn't have much bearing on what occurs in reality, which unfortunately neither of us have much insight into, at least from where I sit. The fact is that Amtrak trains do run late, Amtrak knows that, and apparently either can't or doesn't do much to fix it. I think the fact that they run on a deficit and depend on the government just to keep existing is probably a factor. Maybe Amtrak cannot afford certain upgrades that would allow them to run better.
I don't know if Amtrak shares its tracks or not. I kind of think that they might share their tracks with the local mass transit (Septa around here), but as I only and always ride Amtrak, I wouldn't be able to speak to that personally. I think I have been on Septa once in recent memory.
I don't know if there are any other options around here besides Amtrak and the local rail, which is Septa, and which doesn't go far enough to take me where I want to go, so yes, it's always Amtrak. I was on the Acela once or twice, usually I am on the regular trains.