There's about ten zillion threads discussing this issue over and over. If you want to read them, go google for them, they aren't hard to find. I will, however, point out:
1) I don't go with what I think is the most sensible rule or the best rule or the most balanced rule, always (although in this case, that happened to be the case). I go with taking into account what the rules say, what the community consensus is, and erring on the side of what is least likely to cause a big problem if the GM disagrees. Remember that these characters are made for missions where you don't have a single GM. Only a minority of people think the Sensor rule was meant to work like you do, which is why I don't assume it. If the GM does disagree, they can just run at 1 rating less, oh noes.
2) The sensor rule working like you think it does is the more broken and abusable interpretation, it's just abusable in a different way. You'd probably have noticed this if you weren't so busy making ad hominem attacks. The reason for this is simple: if you interpret the rule the way you do, it tells you that drone sensor systems count as supplying channels=sensor. This means that for a completely trivial price of 125ny, any drone can have Sensor 6 and thus supply 6 channels (do note, it's not a cap of "up to Sensor, depending on how many channels it would have normally," it's equal to Sensor).
However, that only covers the drone's own sensor systems - drones can still benefit from worn or carried sensors separately (this isn't unique to your interpretation, there's just no real reason to do it otherwise). Do note that "drone sensor systems" are very explicitly a thing that is different from sensor systems worn on or carried by a drone, see SR4A 333-334. So, you get a microsensor camera rating 1, put Smartlink in it, and gecko tape it to your drone. The drone sensor systems supply 6 channels (sensor), the worn microsensor supplies 2 (vision+smartlink). You've spent 725ny to get your eight sensor channels, which is about a third of what it would normally cost to get eight sensor channels on a drone.
3) If you really want to be safe and are playing in Missions, you can also just remove the Smartlink on the drone itself, remove some other useless sensor, and put a Microsensor Camera with Smartlink on the drone with gecko tape, thereby making you compliant with both interpretations, and slightly stupid-looking. Of course, if you're playing in a home game, you can just ask your GM.
