For example, in the UK the majority of cars at the level Tesla is going for are business vehicles. In that category, the tax laws make it such that the best thing to do is to lease a car.
Which is why you get business leasing options from every manufacturer:
BMW: http://www.bmwbusinesspartnership.co.uk/
Mercedes: http://www2.mercedes-benz.co.uk/content/unitedkingdom/mpc/mp...
Lexus: http://www.lexus.co.uk/company-cars/company-car-driver/2013/...
Basically, company car perks are paid in cash in monthly installments. Everyone with a business vehicle leases the vehicle using the cash they are paid.
Tesla may sell a fair few cars in the UK, but if they want to put a lot of cars on the road they'll need to package the car in a way that will attract this market.
I'm sure similar market differences exist throughout Europe too, where local conditions mean that buying outright isn't usually the best deal.