The characterization of some of these senders as lazy is simply not true: I once engaged with a student who wrote like some of those examples and was trying to contribute to a FOSS project I ran; he turned out to be an excellent contributor who nobody could reasonably say was lacking in either skill or effort. It is usually just a combination of shyness and excessive respect that produces these 'lazy' requests. And, frankly, using words like 'ur' and 'thx' are how some 100% native speakers of English write. (The ever-relevant XKCD strikes again, #1414 this time.)
I consider myself to be extremely lucky that my native language happens to be the lingua franca of the computer industry if not the world, and even luckier that I don't have any impediment such as dyslexia that would hinder me capitalizing on that good fortune to the full.
And finally, yes, most of what one receives online is spam. Lots of spam, in fact, but when someone makes as least as much effort to contact me individually I try to make at least that much effort in return.