Military survival handbooks are primarily written for soldiers. The equippment they have is usually what was issued. Some equippment may not be the very best for the purpose as some compromise has to be made.
The esbit stove has some advantages. It has the size of a deck of cards even with fuel. It is easy to use. The fuel canīt be spilled and it can be used as tinder. When you decide that you can live with its disadvantages itīs not that bad.
Considering the bulk and weight the stove can be used as backup.
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If it isnīt broken, it doesnīt have enough features yet.