Someone in a position of economic vulnerability isn't going to invest in housing to rent out if there is a non-insignificant chance of damage to the property.
Moreover, this uncertainty has the perverse outcome of pushing the potential small landlord to use his funds to invest in something like a real estate investment fund - which will result in less local control over housing.
I think it’s time the English speaking world realised that landlords are not providing a service, they are extracting a tax on people that don’t have 150K to pay a deposit.
When I was younger I would really like to have more houses to rent... I don't really care if they provide a service or not, it's the cheapest and more liberating option available.
If the neighbors are a hell... I could just move out. Or if the house was not close to a gym I liked... move out.
I can have 150000 euros which I can use in an emergency, like being unemployed, long sick leave, needing move out of country due to family reasons OR I can risk not having it available when I needed and earn some money. Without the profit I have no reason for the risk.
Furthermore, me not investing removes a house from the renting market which makes it harder for people with less income, specially young people. To have a place to live because the same house will be available for purchase through a mortgage... and mortgages are not good.
You have to make a 10% down payment and you're almost always tied to a flexible interest rate... so people with less economic freedom are the ones to suffer the most.
You might disagree that things should not be like this which is fine, I'm only arguing over what happens now.
Unless you are proposing to take his extra 10k euros by force, or let him invest it elsewhere?
If you want him to invest his 150k euros in housing you need to (according to him) lower his risk.