to achieve what you're describing you'd need a high-powered smoke grenade with a very small blast radius. with a power of 10, the smoke blocks little to no vision on a single tile, and dissipates completely in a couple of turns, making it completely useless in any practical sense.
if you reeeeeally want your smoke grenades to do nothing, by all means set them back to 10. but for reasons of playability i'm quite happy to leave it at 60, as per zombie's fix on strategycore.
"it was in the manual" is hardly a viable argument, btw. have you SEEN the manual for xcom1? why would you think the people that wrote the manual had anything to do with development of the game? they were more likely given a copy of the final product and told to "write something".
as far as we can tell there is no good or practical reason why the smoke grenade should remain at 10, if it was intentional then the intent is either completely unclear or simply not achievable with the game's engine. the result, whether by intent or not, is that there is a weapon in your arsenal that serves no purpose whatsoever other than to take up space. - i personally find this unacceptable, and you should too.
conversely, we DID leave the biodrone's melee attack at a hilariously inefficient level, because in testing, it became obvious what the intent was, and it works REALLY well within the game engine.
