yeah, spot-on, it's less IKEA and more the cheap assemble-it-yourself knock-offs you find at Target and Wal-Mart and the like that gives that kind of furniture its poor reputation. IKEA furniture I bought a decade or more ago is still in great shape.
Quality IKEA furniture is made of solid fir/pine/spruce and is finished with a resin paint that resists scratching pretty (though, pine is still soft and dents easily). If you put it together using some wood glue, it will hold up for years.
IKEA absolutely sells cheap furniture made of laminated MDF, and it's often half the price of the quality stuff. And it's not fair to lambast IKEA for sacrificing quality to hit a price-point when they do allow people to pay more to better stuff.
The step up from the good IKEA tier is a big step. Even cheap hardwoods like oak are a lot more expensive than s/p/f. And that's not even getting into how much more wear hardwoods put on tooling or the weight difference.
Half the time it's not even MDF anymore, it's just laminated reinforced cardboard with chunks of MDF here and there for screw points. What I find really sad is how a lot of expensive furniture also uses MDF.
Solid wood is expensive and it does have a lot of seasonal movement. I do some furniture building and there's something to be said for how workable MDF is. It doesn't warp, it's dead simple to cut through, it's pretty light, and it's cheap.
If it's used correctly, MDF is a fine material for furniture. The key to quality pieces with it seems to be in the finish. A piece that's primed, painted with high quality, durable paint, then sealed/lacquered will last a good long while.
