Comping is a competitive thing and it is only in the very rarest of cases that an airline will comp into its top tier. You'd have to be someone like Merry, or Bill Gates, to get that benefit from zero. The lower tiers are accessible, but as I say, competitive factors come into play. If you live in a fortress hub, the dominant carrier is unlikley to grant equivilent status, but might comp the next level down with a proviso to travel a certain amount within a given quarter. A competitor in that market might well give you equivilent status if you have elite with the dominant carrier to get your business.
I have mixed feelings about comping, even though I have benefited recently by having my earned AA status upgraded for competitive reasons (given CP's withdrawl from oneworld and as of next week, from a partnership with AA]. In all cases where I have been comped it was on the basis of flyring a certain amount with that carrier. Either they invited me to participate (NW Gold from Silver) or I made the entree to them (AA Gold Challenge). In each case, I earned the status on a pro-rated amount of quarterly travel, though may not have kept up the pace given my travel patterns. However, that carrier became my alternative choice (from CP) when routes and travel dictated. Based in Canada, my being AA Plat or NW Gold was not really a drain on the program, since I was not competing for upgrades on a regular fashion, and there are no lounge benefits associated with the U.S. carriers.
But as someone who also earns elite status each year on my primary carrier, I do feel a bit peeved knowing someone has gotten the same status by doing next to no travel on that carrier, while I have spent too many hours in the air and an awful lot of cash in the process.
The bottom line is competition. And if it is a factor in the market you travel, then the chances are reasonably good for some kind of comping based on your current status on one of the competitors. But you're extremely unlikely to get top tier elite from anybody. Which I agree with. If you want it, earn it!