I think merged mining is the pool's choice, nothing to do with the devs but I might be wrong
You're wrong.
Merged mining is something the second coin (the one merge mining against the first coin) needs to explicitly support.
It's the choice of the coin devs, not the pools or miners.
In the case suggested for doge/ltc. LTC would stay as is and Doge would hardfork to merged mine against LTC.