By whom ????

For me, entry level is the cheapest bike (at an LBS) for your riding style. It means someone doesn't have a lot of $$$ to spend on a bike right away and/or they aren't sure whether they want to commit that kind of money to a bike.

People will buy high tech thingies like full suspension because they can be convinced they need it. But people who buy $900 hardtails when there are functionally equivalent (for a parking lot) cheapos next to it ($300) typically know what they are doing. If they know what they're doing, they're not entry level. They are an experienced buyer that discriminates between low level and high level parts.