They all have their individual reasons but I'm certain some of the rationale would include:
1. Slow capital equipment sales and with the sales that are realized the pricing is at a level that affects the bottom line.
2. Many lift trucks companies have not exhibited due to costs vs. benefit. Quite often most visitors to your both are from your competitors. Some lift trucks manufacturers tend to lean towards supporting regional shows thru their dealer network vs national.
3. Years ago a study was done it found that 80% of the attendees came from within a 300 mile radius of the show location. And in Chicago a significant part of that radius includes Lake Michigan.