Should tenants have the right to sublet to lodgers?

One of the surprises of the budget was a small paragraph about subletting.
It was in a section called ‘Support for the sharing economy’.
It may be worth quoting the whole section so you can see it in context:
Support for the sharing economy
1.193 The government wants to ensure that Britain is the global center for the sharing economy, enabling individuals and businesses to make the most of their assets, resources, time and skills through a range of online platforms.
This Budget therefore announces a comprehensive package of measures that will break down barriers, create opportunities for sharing, and unlock the potential of this dynamic and growing area. Building on the recommendations of the independent review of the sharing economy, the government will:
make it easier for individuals to sub-let a room through its intention to legislate to prevent the use of clauses in private fixed-term residential tenancy agreements that expressly rule out sub-letting or otherwise sharing space on a short-term basis, and consider extending this prohibition to statutory periodic tenancies
enable government employees to use sharing economy solutions to book accommodation and transport when travelling on official business, where this represents value for money
encourage Local Authorities to use their business rates discretionary relief powers to support the sharing economy, including shared workspaces and makerspaces 1.194 The sharing economy also presents an opportunity to drive local growth and deliver local public services more innovatively and efficiently.
To demonstrate the benefits of the sharing economy the government will launch two pilots in Leeds City Region and Greater Manchester in 2015-16, to trial local sharing initiatives in the areas of shared transport, shared public space, and health and social care.
1.195 These and other initiatives are set out in the government’s response to the independent review of the sharing economy.
There has been a lot of criticism of this proposal for example this post in Property Industry Eye which raises issues relating to rent to rent and HMOs.
However budget paragraph reads to me more like a desire to allow tenants to take in lodgers (as is often permitted in social tenancies) or run a modest B&B business.