Please consider :
- each patriot uses power, means if you build 3 patriots you have -150 power, so for 4 patriots you'll need a powerplant meaning each patriot has effective costs of 1200.
- patriots are extremely vulnerable because of the power, so first thing most players attack are the power plants, meaning that you'll likely have to build a power-buffer to prevent your basepower going offline fast. If you do this - let's say 1 powerplant buffer for 4 patriots, the cost of each patriot increases to 1400.
- patriots are static. With rocketeers you can focus on one entry point while with patriots you have to cover a large area...that said you can imagine that the cost very much increases because you have to build much more patriots...at least 2x or even 3x or 4x more
- if that wouldn't be enough if you have mass-rocketeers many patriots fire at the same rocketeer, so they lose their effectiveness in not having a coordinated defense.
Just think about a base with 8 patriots, 2 patriots each direction, they'll use 400 power = 2 powerplants + buffer of 2 powerplants = 8x1000 + 4x800 = 11200 costs, but you have just 2 patriots each side, means if you attack with 18 rocketeers (10800) you'll face 2 patriots (let's say 3 or 4 if the radius overlaps) and go straight for the power. They will suceed in taking 2 powerplants (needed for the powerdown) out before being killed I'm pretty sure.
If you use rocketeers wisely you'll have no problem in outplaying the cost-use-ratio against the patriots.
And this is even more true for veteran rocketeers (spied lab).