So this statement is misleading.
@ThePongCommenter explained why it is misleading and unfotunately you are still displaying a rationalistic attitude to this. The fact that people cannot serve shirt doesn't mean that you uave the skills to attwck what they send half long. In fact, i have beaten people by *trying* to push short and having them make mostakes because they kept waiting for the obviously long and mistimed the half long that wasn't rushing onto thier rwcket with momentum. In other words, quality can be level relative. Just because i tell you a ball is not short doesn't mean you can read and attack it as not being short.
So it all goes back to that there is little need to overly debate these things orline. You either find a use for them in your game or you don't. Generally, all the playees giving you advice have largely given you enough context for you to either find relevance or ignore it. In the end, the best form, unless you really don't want the advice at all or the person is just being so rude to you you feel the need to retaliate, is to just acknowlege and move on. Not everything someone tells you will help your game, especially if you are not training or competing. But it is all good stuff to start with as an idea if you do train.
I can tell you that as
@blahness pointed out, if you compete, there are players you will almost always want to start out of the backspin game if you have the ability to do so and you also want you give yourself time so going long really fast is not what you want. So yoj go chopping or pushing topspin over the table even if the ball is not 2200 level tight. You know they might open but you find their opening easier to handle than attacking and feeding them topspin to counter. All these things are *level* relative. But they all go back to *your* style. Just because you can't execute a skill at a super competent level doesn't mean that the skill won't be decent at your level.
In fact one of my weaknesses when i wws 1200 was that I pushed literally every serve. And as crazy as it sounds, it worked against many uncoachrd players even up to 1400 because i had a really heavy push. I was trying to keep the ball on the table so i was trying to push *shortish* and make the ball heavy. Obsessing over what people fo at this or that level is not as important as lookijg for skills that fit into how you want to play. Someone gave you an idea, acknowledge it, decide if it fits your game then move on.