There are not many on the first plane because we are a country of laws.
Claims are made that individual immigrants have some special circumstance and we allow them to stay long enough to present it. We bend over backwards to be fair even though we're pretty sure they are just stalling.
If we were the monsters people like to say we are there'd be 1000s of them in the cargo hold of a ship in chains.
These are the ones caught entering illegally. They didn't cross that way because they wanted a paddle. They could have turned up at a port, showed their passport and asked to apply for asylum, but they know they don't qualify so they sneak in and when caught throw their documents overboard.
Many of them miraculously become children once their papers are gone.
As others have pointed out elsewhere they have lost everything. Including in most cases their wives and children who they completely forgot to fetch with them.
Luckily they have their smart phones so they can call lawyers
If they don't want to go to Rwanda they don't have to. They can just stop in France and ask for asylum. It's not as though they are in any danger.