Love that artists in the UK scene would say this. Here in Italy there's still this super common mentality that is still being pushed by a lot of art teachers, art schools and even professional illustration and comic schools that "you can't sell manga in Italy, so you should never EVER draw in that style, not even for practice. NEVER". Which is absolutely ridiculous, if you think that W.i.t.c.h. and Winx, aka two of the most popular Italian series that are known all over the world were heavily influenced by manga and anime. Our "professional" and "100% italian style" comics that supposedly "sell more"? ...They're basically only popular in Italy. A few series had like two/three comic books (out of over 300 here in Italy) published in other countries and pretty much NONE of them made it to the UK/US market. And I'm saying this as someone who loves Italian style comics and never had any interest in drawing manga (except for W.i.t.c.h. comics, lol): even to this day, I still hear students saying that their art teacher in middle school told them that drawing manga was "wrong" and that they shouldn't do it, and I'm just... STAHP SAYING THAT, DAMMIT.
Yes, you shouldn't just copy a style mindlessly without putting any effort on it and you definitely shouldn't limit yourself to one style, but to say that a very popular style is "wrong" and should never be used just because some publishers are apparently still stuck in the 40s and won't see that the world isn't limited to their own little country? Urgh.