There is plenty of room for debate over this advice. Prefer do notation if the effects of the flow are more important than the data structure, and prefer using Applicative style if the data structure layout is easier to understand than the effects to build it. In the example in the article, the software is easier to understand from the perspective of how data was acquired to populate the record. However, this isn't true in a general sense; often records are purpose built in higher level languages to reflect effects and constrain them.
Example: when using Parsec or similar, Applicative style is far easier to understand when examining how records are parsed. In this case, the records will likely reflect the AST, which in turn will reflect the grammar. The two reinforce each other: additional constraints on syntax will naturally flock to data constructors.
There is plenty of room for debate over this advice. Prefer do notation if the effects of the flow are more important than the data structure, and prefer using Applicative style if the data structure layout is easier to understand than the effects to build it. In the example in the article, the software is easier to understand from the perspective of how data was acquired to populate the record. However, this isn't true in a general sense; often records are purpose built in higher level languages to reflect effects and constrain them.
Example: when using Parsec or similar, Applicative style is far easier to understand when examining how records are parsed. In this case, the records will likely reflect the AST, which in turn will reflect the grammar. The two reinforce each other: additional constraints on syntax will naturally flock to data constructors.