I often say grats to some people after landing, but none of the people I say it to need it, nor do I really like it done to myself. I usually respond with a ty just to be polite.
I think it is with a different attitude if you said it to someone who you were fighting, in which you knew was facing many nme, and got a handful of kills and fought is way out of the bucket.
Alot of times, when you see people landing many kills, it's all just spawn camping and vulching....wtg them if you like, I'd prefer not.
Some of the most rewarding sortie's I've flown have not been 10+ kill ones, It's been the ones with 1 or 2 kills against some great pilots. It's not the number, it's the quality. getting a wtg for pwning noobs, spawn camping, ganging, cherry picking and vulching just futher degrades the meaning. I think some use for virtual butt kissing as well.
just my opinion