A sibling comment explained it better than I did, but it's not the comfortable chair or the beer or the lunches or the foosball table. It's the slippery slope of unchecked spending. Plus while an Aeron is a great chair, you can find a lot of great chairs for at least half the price (including used Aerons)

Why you assume it's necessarily unchecked? What you are complaining about are very basic things. Nobody is talking about giving employees daily foot massages, hiring celebrity chefs from Michelin-starred restaurants and having an olympic pool in the middle of the office. Such things could happen, but that's not what we're talking about here. A comfy chair and a fridge with some beers is pretty basic - and not really that expensive. Sure, everything should be in moderation - but what is described it perfectly moderate picture and not some excess luxury. If anything, if I see the company is starting to try to save money on chairs and buy cheap-and-crappy ones, I'd probably look for another job, because there's trimming fat and there's cutting the bone, and proper office setup is definitely the bone.

These benefits are available to all employees at all levels though. Why are people so set on trying to eliminate one of the few benefits even the interns can get to enjoy?

Why on earth would I ever want to work at a company that doesn't value my posture, reduced risk of RSI or the possible ideas/innovation that can come from me chatting/bonding with my coworkers over a beer.

It's a drop in the bucket compared to executive ubers, flights and hotels.