You do get less. You get lower storage space, Ultra-low voltage CPUs/GPUs which lack performance in comparison to the MBP's LVs, less ports, lower battery life, a lack of a superdrive, lack of RAM upgradeability, higher price, and also a widely-acknowledged poorer-quality screen despite the higher resolution. As you said, how much one values each one of these points is a personal preference. I personally don't value the Superdrive that much, but value everything else.
It's okay to prefer one to the other. Different people want different things. What's not okay is to shove one's opinions down others' throats. If people want 13" MBPs over MBAs, they have their reasons, and most of them are pretty legitimate.
In my case, I need more than 128GB of space, and not only am I unwilling to pay the premium for 256GB, I am also not looking foward to having to carry an external HDD with me at all times which would easily offset the weight advantage - the only thing I would actually value over the MBP. In the end, the net result would be a more expensive laptop with less ports, worse CPU/GPU, lower screen quality and battery life, and RAM unupgradeability.
As a small bonus, there had been some rumors on LV i7 quad cores, a chipset that could easily fit onto the 13" MBP. However, it wouldn't fit the MBA's ULV needs. All-in-all, if the MBP 13" gets phased out, that means no 13" quad-core laptop from Apple.