For FM/WL, at least, I'm speaking with my past experiences as a former (and current) scrubby BD having trouble with silver FM/WLs. Even running deflect only helps if you can immediately realize and capitalize on the stun from ranged, which you would not expect from a new blade dancer. Deflect spin isn't a panacea for all of the BD's problems, and given that it's a 0.5s deflect on a ~4s spin, if the BD is just spinning, even a spamming FM isn't guaranteed to proc the stun on every spin that the BD makes.

Also, note that deflect spin removes the movement speed buff from tab spin, so once the BD is chilled he has a harder time playing catch-up.

While I agree that I'm still learning about PvP and other classes, and don't know everything that they can do, I can tell you that from the newbie BD's side, it seems similarly daunting even facing against a newer FM until one acquires a bit more experience with the game. As a scrubby low-gold BD, I only recently started to learn how to fight back against the chills after watching quite a few videos of more experienced players and some research of their skill trees.

Perhaps this is an issue with perspectives? Even back in the bot tournament seasons, the string of BDs that you lost to could very well just be more skilled as players, since Diamond was pretty much everyone back at that point.

It actually takes work and a different build than PvE to effectively apply chill stacks.

You quite literally just apply it with left-side RMB though O_O? Granted, I'm still learning about what the class can do, so if I'm wrong about this please tell me what else you need to apply chill on someone.

Yes, it's true that I'm still learning about Assassins right now (using myself as an example of a new player, remember :)?), but I'm assuming a basic level of proficiency with their class for both players. We have to draw the line between "new player" and "really stretching argument" at some reasonable place, and even if it's harder, an assassin that doesn't even know all the ways to go into stealth and heartstab is a bit ridiculous to use for any argument.

Most new players, regardless of class, get tripped up when going against stealth, making the matchup much more even.

I don't know the games you're talking about. I used to play SSB competitively though and while some classes were harder than others, anybody could play any class they wanted and start out on equal footing. That's not the case in BNS where you're stuck with PvPing with your main character, since the game is so unfriendly to alt characters especially in regards to HM skills. So if you happen to main one of the harder PvP classes like me, tough shit. Especially if you've got rough ping. Because re-rolling a character at this point would be extremely disheartening.

That I'd agree with you on - it's easier to just pick up an easier character in a fighting game compared to BnS.

Still, BnS is pretty honest about the difficulty levels of the KFM and Assassin, at least. I would hope that a new player who chose the class with the highest difficulty ratings is going to be willing to do the research and at least know their class before stepping into the arena, rather than just yolomode it.

Also, keep in mind that a player's mentality is something difficult to change, and regardless of how accessible the game is, that mentality is a huge part of how well a player progresses through PvP. Someone who is immediately willing to blame balance or the opponent's class/difficulty level rather than improve is generally the same type of person that will get stuck at some point in their PvP career and stagnate. Using the BD as an example - a player who keeps on mindlessly attacking into parry spin, gets wrecked as a result, and ragequits immediately while making a capslock post in the forum instead of admitting their own fault and trying to improve tends to not be the type of player that succeeds at PvP in general, and will likely quit at some other stage in PvP once skill becomes a more influential part of the equation.

There are, of course, other factors that are very important - ping, dexterity, reaction time, etc. - but mentality is a pretty big one. This is even the case for fighting games - it's not common for people to overestimate their skill and blame characters for their losses even when they are faced against a stronger player.