WHY VENDORS LOCK IN (AND WHY YOU SHOULD NOT BLAME THEM FOR TRYING)
Let us be fair to vendors for a moment, because I am one. No company locks in a customer out of villainy. They do it because a captured customer is the finest annuity in business: predictable, recurring, and, once your data lives in their format, essentially impossible to lose. If you designed a revenue model from scratch, you would design that one. I would too. The mistake is expecting the vendor to protect you from it. That is your job, and it takes about four sentences in a tender.
HOW THE TRAP WORKS: THE DEMO IS THE BAIT, THE FORMAT IS THE HOOK
The trap is rarely visible at signing, which is what makes it elegant. You evaluate platforms by their demo. The demo is gorgeous: dashboards, maps, a satisfying little animation when the data updates. You buy the demo. What you have actually bought is the lock: the data now lives in shapes only this system understands, reachable only through this system's screens. The demo was the bait. The format was the hook.
WHAT IT COSTS: THE INVOICE NEVER SAYS "LOCK-IN"
The invoice arrives eighteen months later, and it never says "lock-in." It says "data export, custom development." It says "integration, out of scope." It says, most expensively of all, nothing at all, in the silence where a competing bid should have been, because no competitor can touch a system they cannot get the data out of. Your switching cost has quietly become your real price, and you pay it forever.
THE FIX: WRITE THE EXIT INTO THE ENTRANCE
The fix costs nothing and feels almost rude in its simplicity: write the exit into the entrance. Require, in the contract, that at any end the vendor returns all your data, the schemas that explain it, and the documentation, in open formats, and helps you move, at a price agreed now rather than improvised later. Require the data be reachable throughout via an open, documented interface, not only the vendor's screens. You will be told this is unusual. Notice that the people most reluctant to promise a clean exit are, reliably, the people planning for you not to have one.
THE THESIS: PROPRIETARY IS EXPENSIVE IN A TENDER
"Proprietary" is a respectable word in a product. In a tender, it is the single most expensive word you can fail to forbid.
DISCLOSURE
My own software is the open-standards kind, so of course I would say this. I would only point out that "he would say that" and "he is right" are not mutually exclusive.