Overhead Bin Space Angst

In my experience, most of the time, gate agents will offer free gate checking for carry-on baggage.  Normally, I gladly accept this offer:  I don't have to deal with my bag or worry about overhead space.  Most of the time they'll take the bag right away, which is great! Sometimes they just apply a tag and instruct you to leave the bag at the end of the passenger boarding bridge.

On our latest flight, the agents came onto the PA and let us know that there could be no gate checking for; (reasons they gave, but I don't remember the term or what it meant) and so passengers were instructed to put their personal items under their seat and load their one allowed carryon, efficiently. Adding to my angst, was that we had budget seats and would be boarding last, or very nearly last.  We have seen passengers put their bags in the first open spot, even though they are seated much further back and given our boarding time, we could easily get screwed by any such psychopath.

As it turns-out, maybe one small vice prevented a much worse vice.  When we got to our seats, there was space in the overhead bins, but only after rearranging some shoddy packing by those before us.  Maybe the psychos were dissuaded by no clearly open spot to colonize. 

Added and only to remind me in 5 years and I've forgotten by then: In the bin above us a duffle bag was in crossways and space was made for our duffle bag by making both of them face with the long axis running aisle to window. The other bin with space way across from us.  A personal sized item was re-arranged so that it was on its narrow side and a coat was put on top of a shallow item.  This made just enough space for our carryon to be placed on its narrow side.