Why do search engine crawlers not run javascript? [closed]
I have been working with some advanced javascript applications using a lot of ajax requests to render my page. To make the applications crawlable (by google), I have to follow https://developers.google.com/webmasters/ajax-crawling/?hl=fr . This tells us to do something like: redesigning our links, creating html snapshots,... to make the site searchable. I wonder why crawlers don't run javascript to get the rendered page and index on it. Is there a reason behind this? Or it's a missing feature of search engines that may come in the future? Even though GoogleBot actually does handle sites