If it was a great aunt or someone who wasn't immediate family maybe they didn't feel condolences were warranted. I was close to all my great aunts and uncles and 2nd cousins but some people don't even know extended family and may feel phony saying something to you if they don't think you'll miss them.

I wouldn't end a friendship over it but friends should be able to talk about it. Maybe if you wrote that you were close or this was a special relative or whatever, it may help. It could be they really don't know what to say and think they may sound phony. Seriously, you don't realize how nice it is to hear "I'm sorry about your...." until someone you love dies. It's because you're emotionally drained and are trying to still do your daily activities and it's nice for others who are also doing those activities to stop and acknowledge it, it's like they realize your brain isn't all on the same page or team at the moment with them and it's okay but until it happens some people don't realize it's important.