Contractor's work where ever the work is and when ever the work is or isn't. In 12 years I was out of wowrk for at least 1, I had one contract for ~ 2.5 years that was commutable, otherwsie the very best I coudl do was live away Monday to Friday, typically I'd only come home very other weekend. I also spent nearly 3 years working overseas. On one job things went financially pear shaped with the parent company and I was 'let go' with a months notice. If there isn't some incentive to do this compared with salaried staff then some folks will not play.In what way is IR35 a barrier to entrepreneurism? Those affected by IR35 are sole traders or operate personal service companies. Neither involve any entrepreneurial risk. Foregoing sickness pay, pension contributions and paid holidays in exchange for tax and NI benefits is not entrepreneurial risk.
As UORMan observed above the usual alternative for companies that want some genuine temporary staff for a project is a consultancy company at inevitably a lot higher rate. The other advantage of sole operators is when you find some decent ones you know if you go back to them what you're getting; a consultancy company will just pull a bunch of names out of a hat.
The scam is where the staff are not working on short term projects and stay with the same company for 20 years. It’s not hard to spot and the way to stop it is to take on the company running the scam not the individuals.