Is playing through etiquette dead?

I'm out on the course right now making this post because I have loads of time...

Upper Midwest Friday afternoon round, the course is relatively empty as I'm playing as a single. Catch up to the foursome ahead of me on hole 2. I figure they'll let me play through as long as I keep on their tail on how 4 which is a short par 3. I finish hole 3 and walk up to the fourth tee box and give the group about 10 yards as I stand and watch the fourth guy tee off. As soon as he finishes the other three guys bolt towards the green without acknowledging my existence.

Last I checked, it was up to the group being played through to offer it to the quicker group behind them. Should I have spoken up? The whole time they were on the fourth green they kept looking back at me like I was being some sort of dick standing there waiting for them clearly annoyed.

Don't get me wrong, we all hate playing through but when you're a single stuck behind a foursome it's worth the awkward tee shot to get on with your round when at least the next two holes are wide open.