Originally Posted by CyBeR

I disagree because here's what would happen if they didn't stop companions (without status of course) from using the priority lines: someone would figure out that you can simply buy a KL flex ticket for a little extra € which lets you and everyone with you use the priority line which is *much* shorter than the regular line. Groups and families that would otherwise not have access travelling together would have one person buy their ticket on a separate PNR (something real people don't care about) with flex, the rest would get light fares, and once at the airport they'd all come through the SP check-in, the one with SP goes "they're with me" and they all walk up the stairs to clog the priority security line. This information would quickly get out because people can't help themselves and would post their amazing travel life hack on twitter, instagram and facebook, and before you know it most of the passengers at the airport are using this scheme and before you know it we're all stuck in a giant line behind people who have no business being there and, not being frequent travellers, are inexperienced and holding up the line even more.

Oh, and this of course is all in addition to people like the ones I kicked out of the SP check-in line yesterday who thought that they might be skypriority even though they weren't in a premium cabin and fly once a year, and there were multiple such groups.