I find this discussion quite interesting so I' d like to put in my two cents.
I think that the question discussed here cannot be adressed by simply saying "if you lose against a scrub you are an scrub, git gud".
We have to take on account that, in the process of learning a FG there is a huge gap between knowing something, trying to apply it and doing it efficiently (and consistently). Someone that is in this process, call it intermediate player, isn't an scrub by any means, but can perfectly lose against a supposedly worse player due to the fact that many times it is easier to land a move than to defend ourselves against it. I'll explain myself:
As I see it, an scrub is someone that doesn't care about learning and improving. Some of them are merely casuals that plays a FG a few days and inmediately goes for a new videogame, whch is fine, but there are others that really want to win but doesn't care about adquiring a deep knowledge of the game, which is fine too. These players tend to simply search for something that works and they doesn't really care to go further and learn about things such as fundamentals, matchups, adaptation, etc. I want to make it clear that I don't have anything against them and I don't even like to use the term "scrub"; they are not playing the game wrongly, but they lack knowledge in many ways and, in the long run, they end up losing against anyone interesting in learning because they are never going to adquire it. However, in the meanwhile, they usually get a lot of wins.
This second type of these so called "scrubs", while easily beaten by high level players, are dangerous for an intermediate player, specially in short sets, as they tend to use few moves and strategies that, while beatable, are difficult to punish consistently, as it may require high dexterity, very good reflexes, etc. in order to do so. Many times it's way easier to win against another intermediate player than against an scrub that uses just one "cheap" tactic, even knowing how to punish it. And yes, at a high level play there's no such a thing as a 'cheap' move or tactic (if the game is balanced) but you know it is way different at an intermediate level, where most of us (mere humans) still struggle to react to some punishable stuff (it is our fault, of course, but it doesn´t neccessarily mean that we are worse than our opponent overall)
To summarise: yes, blaming your opponent for your loses does make you an scrub, but one can perfectly lose against a bad player without being an scrub or being bad at all, it's part of the process of learning the game. However, it can be fustrating that, after a good amount of practice, a simple sequence of movements can beat you regardless the fact that you know how to punish it.
Edit: By the way, I've found some of the posts here very helpful and full of good advise!!!.