For super quick prototyping, nothing beats DIP, and it's certainly one reason I still use PICs extensively. I can easily get a breadboard running in five minutes with DIP. It'll take twice that long to get an SMD part mounted onto a breakout board.
For hobbieist use and small company small batches stuff, sure. But the point was this is a small niche market. The big numbers and quantities are smd components.
For product development in larger quantities we are talking about at least 3 prototype board releases before a final design is ready.
EMC, groundplanes, oscillations other stuff you want to tackle asap, you can not do that with a different chip package or a carrierboard then the final product has.
I'd agree with that, but, like I say, if I have the choice to prototype with a part in DIP and an SMD part, for a functional proof of concept in the MCU world, I'll almost always go for the DIP part. Production, yes, of course you are right, most of the time it will end up as surface mount, and in fact I much prefer dealing with surface mount to through hole when soldering.
Keep in mind that at the PoC stage, for MCUs, EMC and grounding issues more often than not are not of the greatest concern, even well into the 10s of MHz: the 70MIPS PIC24E & dsPIC33E parts for example work fine on solderless breadboards, even with 140MHz internal clocks. The same is not, of course, true for high speed analogue or high speed digital interconnects, but in the MCU world that is frequently not a problem at PoC or unit testing stage unless there's some analogue stuff involved.
Simply put, I don't want to lose hours designing and fabbing a unit test board when I could have a functional PoC working in minutes.