That may well be true for you, but it certainly isn't true for everybody.

Someone buying a lot of economy tickets for flights lasting three or more hours within the US is likely to value the upgrades into domestic "first" that AA status will get them. Someone who typically pays for business class will probably get more from BA status (and acquire that BA status faster). And so on, and so on -- this has been discussed quite a lot.

It's also worth bearing in mind that the right choice for any particular individual can change from year to year depending on the tickets that person buys and the redemptions he/she is interested in making -- not to mention, for FTers in many markets, the opportunities that are available to earn additional miles/Avios through hotel stays, car hire or credit card use.