Why some companies might not want to outsource tax planning

Companies would be better off investing in tax-related human capital.
Would more corporate tax enforcement lead to more lending?
Fewer audits of small- and medium-sized businesses may leave banks less willing to make loans.
Businesses, want to pay less tax? Choose the right bank
A bank's corporate clients are likely to take similar approaches to tax planning.
An argument for less transparency in banking

Could greater transparency force regulators to intervene unnecessarily in healthy banks?