Microsoft Access requires more training (tables, foreign keys...) and from experience most of the people using Excel managed to bend it to do what they wanted.
The maintainability of the resulting systems was not great, but they did the job and worse is better I guess..
Add in to that: programming VBA for Excel spreadsheets is extremely trivial; programming in VBA for Access is second worst only to programming in Visio, MS Office's awful drawing program.
The maintainability of the resulting systems was not great, but they did the job and worse is better I guess..