The Financial Conduct Authority's (FCA) asset management market study shows the regulator refusing to take responsibility for reform, according to Simon Bussy, director at consultancy firm Altus.
In the market study, the FCA recommended that fund houses be clearer about the benchmark funds should be measured against and about the objectives of the fund.
Mr Bussy said: "The objectives and intent of what the FCA have highlighted are sound. But it is the execution that could be the problem."
He said execution could prove problematic as the market study does not include examples of best practice when it comes to providing clarity of objectives, or examples of bad practice.
Nor does it include a glossary of consumer friendly terms and Mr Bussy said this means individual fund houses will be confused about how to do it.
He said: "Some will just continue as they are and others will try other methods. The FCA is not taking responsibility."
The particular paragraph of the FCA's market study that caused concern for Mr Bussy state: "We do not currently have any plans to publish examples of good and bad practice, nor do we plan to publish a glossary of consumer-friendly terms.
"Fund managers will need to consider whether consumers can reasonably understand the objectives they set out."
He said: "This is the FCA waving a flag to highlight that there is a problem, which is fine, but then they lack the courage to do anything about it.
"Something like 80 per cent of all the money in Isas is in cash Isas that do not pay even the rate of inflation.
"People want their money to grow, but the industry is hung up on complexity and confusion, the complexity can seem overwhelming, so people are leaving it in the bank.
"An example of people's desire for change is that Marcus, a bank recently started offering accounts in the UK paying 1.5 per cent, and they have received billions in deposits. That is for a rate that doesn't keep up with inflation."
The FCA declined to respond to Mr Bussy's criticism.
Responding to the FCA's study, a representative of the Investment Association, a trade body for fund houses, said the organisation "looked forward" to working with the FCA on implementation.