Would this upset you ?

It bothers me too but just ignore it, you do the right thing. 

Avoid taking it seriously so long you understand the text .If he is a guy interested in you it is crazy to use abbreviations and slang.He should respect you and use words that will give the feeling that he like you more than a friend.This is typically the way how college guys act .Avoid taking him seriously and ignore his texts. 

Ask yourself is it worth losing your mind over the word 'u' or 'ur'?

I know people who text 'K' instead of 'OK', let alone apostrophe. 

If it bothers you don't reply by text, call instead. I feel it's not worth fussing if you want to save the relationship. You'll get use to it.

So if he was still a friend, you don't mind him texting 'u' or 'ur'?

Give him a break...

Failure to use entire words, correct spelling and punctuation, makes me think the person doesn't care enough about me to bother. I think it's insulting.

Aww he does like you then since he said sorry. 

Well, he might be bothered by not using 'u' or 'ur'. Would you change?

You're taking this way too personally. In your mind he's doing it intentionally and you think it's what...? His way of passively aggressively telling you you're not important?

It's probably just how he texts. The way we all text is habit. It's not personal or a way to send some signal to a person their importance or lack thereof. 

Unless your entire text session with him is lacking and he seems bored,uninterested or uninvested,. 'one word replies etc'. Don't judge a college kid too harshly on using text shorthand. We all do it sometimes. 

Every man knows if a woman asks a guy to change something and then he changes, the woman will lose interest because she will see him as weak. Don't blame him for it, blame women's screwed up brains.

I think it’s nothing to worry about. Maybe he’s just tired. Or not a good texted.