Its not racist. They ARE a Korean site and obviously their Main site is in korean and the one you visit is the english site with the translated webcomics to English. Under that way of thinking of yours then WT and Tapas are also racist for only publishing with english as main language (even to the recent years they have been opening Spanish versions and moving to other languages)
In my experience with asian cultures and their work culture, westerns wouldnt be able to follow that strenous schedule and publish weekly. In Tapas or WT you are more free to update when you are able to do and maybe only the ones that get picked by staff under contract has more pressure but more support from editors.
2 years ago, I messaged Lehzin to know their requeriments and were very hard for me (since I have a full job) but reasonable if you are really dedicating yourself to that artistic work and finish your deadlines.
They liked my art but I didnt had anything made yet so they gave me the requeriments to publish with them (idk if those has changed now, you might ask them by e-mail)
The 2 main requeriments I can disclose are:
1.- every chapter/episode must have a minimum of 74 panels
2.- I must have completed 15 episodes in advance before publishing the first chapter.
I know myself and I knew I wouldnt be able to fill these requeriments because my first language is not English, Im slow at drawing and I have a full time job with a weird schedule that will mess any plans I would have for my art projects, so I didnt went far with Lezhin but I know they are open to international artists that fulfill these requeriments as PROFESIONAL ARTISTS under contract.
so if you work under those circumstances and your story is liked they will not give you any problems.