What would you suggest instead :) ?
So either:
- put a ballpark prize on it (even something vague like "from X$ to Y$ depending on application, talk to sales" would work
- if that isn't what you want, you need to make extra sure that people want your product so hard they are willing to jump through your hoops. For that to be true they have to be sure the thing you offer solves problems worth solving in a way they want it to be solved.
But it persists because it works. I suspect call for pricing works as well. Especially for enterprise, and they are who you are usually targeting with that kind of prices.