Recons are notoriously easy to see once you recognize that they cause diagonal distortions on horizontal and vertical patterns, resulting in a paradoxical sense that an object that is normally flat appears to be much more fuzzy than expected.
Being cloaked does not stop your footsteps, either. I've killed cloaked Recons through sound alone.
Also, HEAT vision allows you to see Cloaked recons, so it's not like you're firing it blind.
The best counter to a cloak of oracle. I personally don't think cloak is op in moderation. Until you go up against an entire team of cloak/smg recons without and oracles on your own team. But that is just dumb.
Edit: Didn't realize heat made them show up plain as day. Cool.
You can see the hits that Heat delivers and thereby the positions of the people being hit. Hint to Assault types, let other's know what you are seeing. I.E. 'two targets top right platform, 1 under pipes left of point', etc. Works almost as good as Oracle.
If you're afraid to die, then that is all you will do.
One of the suggestions I heard someone offer was that the recon default weapon ought to be an smg instead of the sniper. At least that way, if you did find yourself with a bunch of new recon, they would be forced to learn how to actually play the game. I think this would have to correlate with a price hike on the low level snipers as well. Recon as a class are very balanced, and simple to counter once you get used to the mechanics, but the population imbalance needs to be addressed.
I know what you mean. When people first pick up the game they see the recon class and droll over being able to sit invisible with a sniper rifle. I wouldn't worry about it too much, you can always go into matches with a fireteam and stay more organized that way. Other than that, this wouldn't be that hard of a fix.