Concerning your first point : being dilated alone may not be enough to warrant an immediate hospitalization. My wife waters had broken, she was dilated a bit, yet it took her another 28 hours to give birth. She wasn't in labour, as such. Only reason we had to stay was that the waters had broken and that's a condition that needs monitoring. But I was told to go home and rest for a while, after 8 hours (we had arrived at 2am).
In general, one of the most important thing to do to help the mother give birth is to feel comfortable, relaxed, etc. Being in a hospital isn't generally conducive to those things so if at all doable, it's better to stay home and wait until it's actually show time. But yeah, not easy to judge, when you're not an ob/gyn!

Your second point is just... there is nothing to defend, there.