>>To me it looks like a no brainer. When creating a primary key for a table I use a guid.

We used SQL Server autoinc/identity fields starting in 1996. Problem is that unless you knew back then to seed the Identity at -2 billion, INT tops out at 2 billion which sounds like a lot unless you're deleting and re-inserting rows frequently which can chew through the increment very quickly. Path forward possibly involving bigint though that will involve some FK issues and VFP doesn't have that field type. GUID obviously avoids all this, at the cost of bulk and possibly less efficient indexing if you can get away with INT identity.