FT.com reports that The American Federation of State County and Municipal Employees (AFSCME) wants to break up Citigroup Inc. (NYSE: C). I agree with AFSCME on this point and that cost me an appearance today on CNBC's Closing Bell with Maria Bartiromo.

Why does AFSCME want Citi to break up? Its Employees Pension Fund long has had concerns about the viability of the Citi business model and thinks that now is the time for a bold plan to restructure the company. FT.com notes that AFSCME believes that [Citi] "operates more like a run-down department store than a financial supermarket." I agree with the union about breaking up Citi.

The concept of a financial supermarket is deeply flawed for three reasons:

• Don't keep all your eggs in one basket. People don't want to put all their financial services business with one company. It's too risky and gives the supermarket too much control over the consumer's finances.
• Diversification is a flawed rationale for corporate strategy. The concept that the different businesses offset each other during business cycles is not supported by the facts. Right now, Citi's consumer and commercial businesses are going down the tubes simultaneously.
• Complexity makes it hard to hit the numbers. Citi is way too complex to manage in the sense of driving steady earnings growth every quarter.