Why Are Transformers Rated in kVA, Alternators in kVA, but Motors in kW and ACs in Tons?

Why Transform rating in kVA, not in KW? as will as Alternator, But Motor rated in kW, while AC (Air-Conditioner) rated in Ton? Please explain. Thanks in advance.

Copper losses ( I^2R)depends on Current which passing through transformer winding while Iron Losses or Core Losses or Insulation Losses depends on Voltage.
Ref: http://www.electricaltechnology.org/2012/02/why-transformer-rating-in-kva-not-in-kw.html
Thats why the rating of Transformer in kVA,Not in kW.

A transformer is rated at the maximum reactive, apparent, or real power it can continuously transfer. It can be operating at its limit, transferring only reactive power and no real power.

A motor is rated in kW because that is the amount of power it outputs as mechanical motion.

A ton, when used to rate cooling capacity, is equal to 12,000 BTUs. This type of ton is the energy required to melt one ton of ice (32 deg F) in 24 hours.