* Hi , firstly I have no link to the article above reverting your 'vandalism' as you would have seen if you looked at the edit history 
 : There are ways to get a page delete on Wikipedia, and just blanking it is not one! You didn't even add an edit summary to explain the reason i.e. "redundant, covered by global article". They are: 
 ::* Speedy deletion - but none of the criteria really apply 
 ::* Proposed deletion - This would be the one appropriate to your reasoning, if you so wished to propose.  
 *I agree that the article, at least in its current state, is not good. It's also un-sourced which is very bad, and as you pointed out it only has speed, which is just one metric of a coaster.  
 *Anyone is free to make one for their own country, or another country, if they want to - just like the lists of tallest buildings for each country, city etc. for instance List of tallest buildings in Cincinnati - If an editor had to make one for every country or none, then articles would never get created. Instead, the way Wikipedia works is that someone makes one article about a subject, say for their country, and someone uses that idea or structure as a base for one for another country. 
 *In the end I really don't know if there is enough information per country to justify a per country version - I'd ask someone with an interest in coasters..... which you appear to have as your second edit  on wikipedia was about a the similarity between a UK and Taiwanese coaster. Instead of just deleting you could have just talked to the creator  about your concerns. Alternatively at the WikiProject Amusement Parks. 
 *All your other edits look constructive, so I know your not a 'vandal', you just expressed your opinion that this was not needed article in the wrong way. So if you choose to ignore it, or talk to the creator or wiki project, or propose a deletion its up to you - all are constructive inputs into wikipedia. Have fun, but respect others. Cheers