Earlier quoted context omitted.
> They all have [their] merits That is a poisonous meme which should be fought tooth and nail. It basically follows the structure of the fallacy of grey¹: "every tool has qualities, therefore they're all fine". It doesn't account for the fact that some tools dominate others. Meaning, they are demonstrably better in every way for every foreseeable usage. But we tend to cling to our old ways, instead of just saying "oo…
Who made you the authority of what is "better"? Decisions to use tools comes from context, and there is nothing wrong with choosing a tool that fits the job. Are people who say that "every tool has qualities, therefore they're all fine" always trying to say that it does not matter what tool you use? If they are worth their salt, they will choose tool A if tool A works and is "better" than B, but will not assume B is…
Now it doesn't mean we shouldn't be weary of sentences like "right tool for the job", "every tools has qualities". While they are correct generalities, they are often used to justify not to change habits: "We'll use C++. Don't say that, every tools have qualities. Besides, this is a big project. Languages are just tools, and you better use one that fits the job".
You could try to go against this trend: "But, because it's big doesn't mean we have to use C++. It doesn't mean you have to use only one language. It doesn't mean you have to squeeze every cycle out of your CPU. What about C + Lua? Simplicity by default, and speed where you need it".
But if you have to overcome fear of changing one's habits, this won't be enough.
Also, you seem to think that no tool dominates another. With that I disagree. Let's start with a contrived example: Lisp vs Blub, where Blub is Lisp without macros. I think it's reasonable to say that Lisp dominates Blub. A similar reasoning led me to think that ML dominates Java and C#[1] (at least if I pretend libraries don't exist and programmers know ML).
Sure, it hurts feelings to say to someone that his favourite tool is strictly worse than some other tool. But it doesn't make it wrong.