If the demo nerfs are reverted, at least they should add teching cost and for example include a side muni upgrade to engineers that allows them to then lay down demos and excludes sweeper and flamer.
If they really wanted to go that route, do you think there should be a specific "can lay demos" icon like there is a minesweeper/flamer icon? Since if so, that just makes actually using demos incredibly difficult because it'd be far easier to tell where to sweep for them.
Frankly, after having played with them for a bit, I like the way 1.3 demos are implemented because they're a good attention checker—if you just click and blindly send a unit to cap a point, you're liable to lose that unit. If you're paying attention, you can at the very least smash the retreat button and lose nothing but time. The timer also synergizes well with the entry/exit delays in garrisoning to punish building use without being abusive against wandering infantry. It's pretty much the best way to handle a "click boom" squad wipe tool.