Bags. I've only just found this topic and you've got company! I'm shoulder to shoulder with you.
Of course language develops and adapts it always has done. These abbreviations are for fast, throwaway texts. That's all.
They amuse me. I find them (usually) witty; gr8 = great is perfectly clear, and it's faster. It used to be cheaper too but that's changing.
I find "thx" more friendly, less stuffy than "thanks". Or maybe some might say that "thanks" is unacceptable, it should be "thank you". Certainly when I was at primary school in the early 1950s, "thanks" was seen as an unacceptable Americanism. Are we resistant to all change, at all costs? I hope not. All that matters is clarity, getting your message across. That's my view 
Funnily enough my younger son, now age 21, gave up all textspeak when he was about 15. Conscious decision by him. He disapproves, thinks it's sloppy and never uses it. I think he fears it'll disadvantage him if an employer ever spots him using it. Shame that the young are under such unnecessary additional pressures.