Having lived in France for o.15 years - it is a hard country to live in. Lots of form filling and beaurocracy. Wherever you settle - the Commune and Maire know you are there and report your presence - the tax people are on to you to register within months (even if you are still living with half the house covered in canvas) and if you want any sort of health care you need to register and get your Carte Verte.
For this, you have to prove that you are in receipt of a pension or other funds. If not a pension, then you have to pay into the URSSAF (equivalant of NHS) according to your income.
France is very structured and it is not easy to disappear or work under cover. Whilst I was there an English chap set up as a jobbing builder/odd job man a few miles away (I only heard of him later on).
He had not registered as a business. The gendarmes watched the local DIY stores, noted the purchases and eventually turned up at his home. They saw the completed house, piles of bricks and building materials filling the grounds; told him he was illegally running a business; confiscated his passport and vehicle until they had a clear picture and then gave him passport and car back, together with a booking on a ferry to UK. Everything else, including his house, was seized and he was forbidden re-entry to France.
This may have something to do with it - oh! and it's a tricky language to learn and they won't change their ways to suit immigrants. It's just a bit different to the UK. Does that help?