Rotem-
Each wikis is, after all, an independent internet website.
Wrong. Each wiki is part of the Wikipedia/Wikimedia project and has to follow some rules and conventions that are largely identical for each of them. All wikis are based on a common codebase; changes to the individual codebase of a single wiki are not allowed for the reasons I have given on wikitech. Each and every Wikipedia is governed by Jimmy Wales of Bomis.com as "benevolent dictator".
If you want an "independent internet website", set up your own one. However, I doubt that the majority of the Hebrew users shares your feelings.
I find it really boring and dull that all the wikis look and feel the same.
In usability, "boring and dull" can be a good thing. It avoids unnecessary surprises. With 20 or so websites, having a different look and feel for each of them will be confusing and annoying. If you want better skins, make one. Every user can experiment with skins if they are tired of the default look.
A basic rule in marketing is to satisfy your audience. Since the audience of, for example, the Hebrew wiki, is not the audience of, say, the Polish wiki. I think each audience should have the right to choose how their website would look and work.
"Each audience" should have the right to participate in a vote to determine the default skin for the project as a whole. Once we have improved the standard skin to be somewhat nicer looking, all wikis should use it, including Esperanto. That's why it's called the "standard skin".
The argument that all wikis should be identical because there is a minority of bilingual pepole
Bilingual people are hardly a minority given how the international school system is set up. Almost anyone who had another language in school can understand it on a basic level, which is sufficient to do stuff like interlanguage link insertion. Furthermore, this is hardly the only argument you have already been given for not having a different look and feel for every Wikipedia.
Here's a better argument: I will design the hebrew site so it will be very intuitive and will take almost no effort to learn how to use it, yes, it would be different but very easy to use.
No. Here's what you can do: Design a skin that you and your readers like. It will then be a user preference for all wikis. If an international majority approves it, it can be made the international default.
What you most certainly WILL NOT do is make changes to the Hebrew wiki without these changes going through the standard Wikipedia code approval process. I have explained this before and I will not explain it again.
Regards,
Erik