A number of reasons for this. Firstly, it is never a wrong thing to follow good practice and keep to the same good habits.

Travelling with the forks tilted slightly back is always going to be the safest method of travel, regardless of being laden or unladen. So get into the habit of doing it regardless of what the neighsayers think.

We already know that applying sufficient stabilising back tilt when carrying a load not only helps stabilise the load and the truck but it also ensures that the load centre or centre of gravity of the load is reduced which stabilises the truck further. A good thing.

Applying back tilt when un-laden (your op question) serves a number of purposes. It keeps us in good practice for carrying loads. It also sets the forks into a safer position to allow for any sudden changes or variations in the ground or terrain and therefore reduces the chances of your fork tips digging into the ground or contacting hazardous objects such as kerbs etc and throwing you through the mast! Not a good thing!

From a general safety point of view, the positioning of the fork tips in relation to a pedestrian's body can be crucial in case of impact. With the forks tilted forward or level during travel, you are likely to hit a pedestrian in the ankle area. With the fork tips tilted slightly backwards you are more likely to hit a pedestrian higher and in the shin or leg bones. It is far easier to repair a damaged shin/leg bone than it is to repair a damaged ankle/tendons/achiles heel etc. Crippled for life time!

We could also add that in the majority of material handling environments that we find low lying electrical items such as sockets and cables as well as pipework for water and gas. These are usually situated at or around ankle height too. I'd try whatever was needed to avoid touching those with a large chunk of steel pointed steel.

So, when you get back to work simply ask your colleagues if they would rather spend 8 weeks in plaster with a broken leg or a lifetime in a wheel chair with facial plastic surgery?

Never ceases to amaze me the discussions and opinions operators have over the slightest of issues. If someone has an issue over something as mundane as adding a little more back tilt when travelling un-laden then perhaps they shouldn't be operating a truck and should be attending the latest mothers meeting instead!

What surprises me even more is that the OP says in his sig that he is an ITSSAR FLT Instructor? This is basic stuff. Should know better!

Hope that answers your question on why we need to apply back tilt when un-laden.

I wouldn't mind betting that your colleagues also argue about wearing a seat belt or the need to wear rubber gloves when checking/topping up the acid levels. Perhaps they also disagree with selecting neutral and applying the handbrake before using the hydraulics?

Cheers

Jonah