What I find much more bizarre than their reaction is that a) this concession was ever a part of the agreement to begin with, and b) that both the Times of India article discussing it (linked above) and the World Politics Review post that linked the ToI (I love me some Off-The-Radar News Roundups) seem to take the tone that this move by the general is unwise. ("The stance is in contravention of the 2006 peace accord that put an end to Nepal's insurgency, and already destabilized the country last year when the previous chief of staff adopted the same position.")
I don't know if there was a different way that General Gurung could have gone about this, but integrating several thousand rebel forces with strongly demonstrated disloyalty to the state into your armed forces en masse, in the context of a very recent total breakdown of state sovereignty, is a recipe for disaster. Wikipedia says that the Nepalese army is 95,000 strong; it does not, however, say how it knows, and despite the surprising excellence of the website of the Nepalese Army, I can't find such numbers there. If Wikipedia is correct, then 6-7,000 Maoists (this being the conservative claim from the Times of India) in an army of 95,000 is not nothing. Even if you split them up pretty extensively you could have real problems with cohesion, authority and morale.
Look, Frederick the freaking Great understood this (per a deeply pompous* series of rebuttals to Machiavelli constituting the aptly named "Anti-Machiavel"). It seems reasonable to me that General Gurung, in the advanced year of 2066 in the Nepal Sambat calendar, should understand it too. I can't pretend to know much about how this agreement came about in 2006 (the Gregorian calendar year, not Nepal Sambat)--while I do need to make a bit of a study of Nepal's situation as an ancillary case to my thesis, I haven't gotten to it yet--but all I can say is that I hope this concession was a highly, highly necessary one.
General Gurung has some pretty good suggestions for what to do with the People's Liberation Army instead, if you ask me:
Gurung said the PLA could be accommodated in the police, border security forces and other non-military agencies. They could also be sent overseas for jobs or be rehabilitated with an economic incentive.
Meanwhile, the PLA seems to be acting in pretty bad faith, waiting for an excuse to break the agreement:
Gurung also expressed concern at Maoist chief Pushpa Kamal Dahal Prachanda giving training to the PLA in their cantonments and urging them to be ready for another revolution if the government failed to implement the new constitution by May 28.
And, of course, what would be an attempt at post-civil-war reconciliation without a "you first" standoff:
There is growing uncertainty over the fate of the fighters with their own leaders saying the new statute should be promulgated before they are disbanded while the ruling parties are demanding the discharge of the PLA first.
At any rate, I currently feel quite a bit of sympathy for the good General, who seems to be very sensible and is being asked to do something that seems to me to be rather less sensible.
*Actual excerpt from Frederick the Great, I kid you not:
Where do these examples leave Machiavelli, and what comes of the ingenious allegory of David refusing to fight Goliath with the armor of Saul because of its weight? It is a lot of whipped cream! I admit that auxiliaries sometimes inconvenience princes, but I ask if conquering cities and provinces is not worth a little inconvenience.
Upon first reading, I recall picturing David facing up to Goliath covered from head to toe in whipped cream armor. Oops.