Here's my two cents. If you've been using the same procedure and relatively similar kits for 30 years and you like the results, then you're really only saying you're completely happy with your process and the beer that results from that process. That's fine, but unless I'm missing something, you don't have enough data to say that you might be bucking conventional wisdom and that you can make just as good of a beer by fermenting at high temperatures, not worrying about oxidation, etc., etc.
What you would need to make these claims are the proper CONTROL experiments. For example, have you taken the same kit, fermented one at 40 Celsius and one at 20 Celsius and compared them side-by-side? When you do that, you may notice quite prominent off flavors that you had no idea existed in that 40 Celsius beer. Take this same side-by-side approach and apply it to any other variable that you think you're finding doesn't matter that much and you'll start to really whittle down how different fermentation variables affect flavor.
Until then, you're really just saying that you're content with the beer you've made under a given, roughly similar, set of conditions for the past 30 years. And there's absolutely nothing wrong with that. As was said before, consistent technique ensures consistent results...