Why not remove the duration restriction on planet traps? i just got to thinking about Temple of doom. Indiana Jones deals with traps that have been around for hundreds of years. why would a trap just decay like that after 1 or 2 weeks? also. it gives the user notification that the planet is under attack and allows a better chance to respond to the attack as now there may be some defenses in place to buy you a couple precious seconds. Even if you arent online during the attack users with hundreds of planets and real life jobs can have the chance to protect his/her property, should the invasion attempt fail.

also it kind of makes some of the more rare traps (exo-rift, Drannik swarm) conceivably useful. in that they are up when you NEED them to be. instead of having the foresight to save them until you need to hastily put them up in an effort to race the opponent to the invasion attempt.

Most of the traps you get enough of that if they lasted until activated you'd end up getting a bunch extra. The rare traps, though, are powerful enough that if they lasted forever they'd be pretty unbalanced; having a Drannik Swarm Trap on all your planets would make your planets far too easy to defend, after this most recent update. I think they should change the Exo-Rift one somehow though; as it stands I wouldn't end up using them, because I wouldn't want to waste it but if I knew the planet was under attack I could just use a Vortex Deflector.

well first consider that traps once triggered don't last forever. they last 12 - 24 hours. and when they do trigger their stats are usually vastly outnumbered by the attacker who doesnt have fixed stats.
There is a point where an alarm sentry or even a Drannik swarm trap means nothing to an invader.

When a trap is triggered it isn't an End All to the invasion. but it provides a layer of Defense. which gives a slight advantage to the home team (the defender). which is as it should be. increasing the chances that the invasion will fail. but only by a small amount, 10% maybe to someone with say 3k invasion power.

then consider that with the sheer number of planets for level 200+ people that need defending (50 planets. 1 every 4 levels), no one can keep up with that level of demand on a daily or weekly basis not with artifact points anyways. and with the number of traps that go on a planet thats a lot of clicking and sifting through a giant stockpile of artifacts.

now look at the levels on the leaderboard. there are a lot of people with 100+ planet slots. can you watch those all the time? even when you arent online?

You don't need to watch all of them all the time; most of their planets probably aren't particularly worth defending, and they certainly get enough traps from AP to protect the really good ones. And your solution does nothing about the fact that the effects do very little anyway. The only trap I think they should work on, besides the Exo-Rift like I mentioned, is the Grav-Whip Trap, but only that they should make a mission for it like with the Omicron Mine Trap, where you turn it in for a trap that is a lot more effective. I guess the Exo-Rift could be a permanent trap, because it's limited in quantity, but not any of the traps that are unlimited.