Some adult learning in England is at risk because of the government's focus on "skills and employability", MPs say.
MPs say a "national learning model" should be a priority
The Commons education and skills committee said the decline affected not only leisure courses for the middle classes but also deprived communities.
Chairman Barry Sheerman said ministers' mantra of "more plumbing, less Pilates" grossly over-simplified the benefits to be gained from further education.
The government said the reforms it was making would revitalise the sector.
The select committee said it accepted that within limited funding, "difficult choices" had to be made about what was paid for by the public purse, by learners themselves and by employers.
But investment in priority areas was leading to "unacceptable declines" in learning opportunities which actually contributed to key government priorities of improving people's basic skills.
The MPs said: "Fundamentally, we argue, the dividing line between what is of value - to individuals and to the economy - and what is less so, is nowhere near as clear as is currently implied in government rhetoric."
Courses, once lost, were difficult to replace.
The committee called on the government to spell out what "skills and employability" actually meant.
Mr Sheerman said: "Many courses available to adult learners are helpful to their careers and should be recognised as such.
"Whilst I welcome the government's recent statements on the importance of further education, the department still has to improve its planning and funding framework, and to spell out to colleges the practical implications of its policies."
The University and College Union said it and many other organisations, including some employers, had argued that courses that might not be linked directly to specific occupations nevertheless taught "soft skills" needed for working life, and so were often an indirect route into jobs.
The committee's report also described the planning and funding of skills training as "incoherent, over complex, burdensome" - often a barrier to further education's development rather than a support.
And it said the government should do more to ensure learners' views were taken into account by college managers, on the grounds that student representation was "one very important way of improving the quality of provision".
The Further Education Minister, Bill Rammell, said the government wanted a word class system that was truly responsive to learners and employers.
Its planned reforms would revitalise the sector and make it "the engine of growth".
The Association of Teachers and Lecturers (ATL) said it was disappointed the committee had not taken "a much firmer line" on closing the funding gap between schools and colleges.
General secretary Mary Bousted said: "It is extremely disappointing that the pay and conditions of staff in further education have still not been addressed.
"The funding gap between schools and colleges should have been dealt with as a matter of great urgency, rather than merely calling on the government to explain what further action will be taken, and by when."
'Reducing red tape'
The chief executive of the Association of Colleges, John Brennan, said the report was "a thorough and comprehensive overview" which picked up on a number of the critical issues.
"We also welcome the prominent call to ministers to be more upbeat about the sector," he added.
The Learning and Skills Council said it was already working to reduce red tape and boost quality through radical reform.
Its director of strategy and communications, Rob Wye, said: "Colleges and other providers are the bedrock of a dynamic and competitive economy and they need to be recognised as such. "
He added that administration costs had already been cut freeing up funds to spend on "front-line learners".