First of all, the USA has deported people to their "home" countries even in cases where they were in their 50s or 60s and were deported back to a "home" they had left at the age of 6 months and had been green card holders for decades.

But if the answers you are getting are confusing, it's mostly because the question is confusing -- if you are legal, permanent resident, why would there be any issue about arriving on a one-way ticket? By asking, you are suggesting it might be an issue, now you are confused that people are trying to respond to your question. If you don't think that should be an issue, why did you ask?