I don't disagree, it's just really not a big deal at all. You gain items fast enough freely anyway.
Not fast enough for me. I still don't have my Sydney Sleeper or any of the Shogun items, let alone the 20+ Uber Update items. Meanwhile, enemy soldiers are wasting my scouts better than I can waste theirs, not out of skill but out of paying money to get the upgraded rocket launcher, and that makes me feel pretty resentful.
It also makes me fear a slippery slope. The Mann Co. Store originally didn't sell weapons. Later it did, but there were only a few. Then there was the Australian Christmas update items, which at first you had to buy festive keys to unlock. Now there's 20 new items, and some of them are more advantageous than normal, and buying is the only reliable way to get them. Valve wouldn't be able to get away with selling, say, a radar device that shows the positions of your enemies, but a year ago, they wouldn't have been able to get away with selling the Liberty Launcher. Taken gradually enough, they probably could turn TF2 into Pay2Win, and now that it's F2P, there's more incentive for that than ever.