I live in a city where a lot of people come for a few years and then move on, and where a lot of the jobs are 1 - 3 year contracts, not permanent, in an industry where moving from city to city - or country to country - is very common.
Many people who are here have no interest in buying at all, but don't want to live in a small flat or shared acommodation. There is a huge market for nice, high quality single family rentals. Why should people be forced to buy when they neither want nor need to?
34.5% of the population in the UK rents. Elsewhere in Europe that goes even higher - it's 48% in Germany! We need better quality rental homes and stronger laws protecting tenancies, not fewer tenancies (which is what you mean by getting rid of BTL, essentially).
And we need the councils to start replenishing their council housing stock instead of selling off homes. Right to buy has been a disaster for this country. There should be safe, enjoyable council-owned housing available for everybody who needs it.
The obsession with owning just feeds the banks - as does BTL, to be fair too, of course.