This is one of those situations where everyone feels like they're an expert. But, in my opinion... not everyone uses KB+M or a gamepad enough to be an expert with both. A lot of people stick with what they enjoy, and in reality, that means their EXPERIENCE is quite limited. That said, people are still going to want to share their opinions, and that's fine.
As someone who has played everything from space sims to strategy games with keyboards, mice, and gamepads, for almost two decades now, all I can do is provide my opinion.
In my opinion, each device is better at .... what its better at! A tool is a tool, and if used wrong, will produce worse results.
Strategy games like Command and Conquer can be played with gamepads, but it is simply easier to do with a keyboard, for most people. However, if you start off playing this game with a gamepad and then after many, many hours go and try playing it with a keyboard, it WON'T appear easier to you, because it will be outside of muscle memory territory. So, your opinion will be biased.
You know what matters, really? Are you enjoying yourself? If you can say yes, then do whatever you want.