Google “Strongly” Recommends Not Using Meta Refresh Redirects - SEO Roundtable
I think we kinda knew this and I bet it’s more to do with people using dodgy SEO tactics than anything else.
You’re right - I’ve just done a bit of Googling and realised that I misremembered something - I knew that most search engines treat a meta refresh as equivalent to a redirect, but what I’d forgotten was that that is only true when there is a timeout of zero - so yes, you’re absolutely right that as long as the delay is >0, it is a technique that spammers and scammers can benefit from.
Stevie: It’s pretty simple, a common scam using META redirects are that you have a page filled with meaningful content with a delayed META redirect (so it only happens after say 5-10 seconds) that way the user is drawn into the page and suddenly gets yanked away to perhaps a scammers site trying to get you to pay for something (or something filled with porn) or whatever else. While search engines now seek out the element, it’s worth pointing out that it used to be a very real issue where the spider would index the good content and the user would get snatched to the other. 
I would guess it’s as much about people who simply don’t know any better, rather than deliberate dodgy tactics. It’s dead easy to teach even the novicest of novices to use a meta refresh redirect, whereas a proper 301 redirect requires a little bit of knowledge. There’s also the problem that some hosts don’t allow you to use a 301, so if you need to change the URL of a page, you have no option but to use a meta refresh.
I’m not sure what “dodgy SEO tactics” would be easier with a meta refresh than a redirect - not saying that isn’t the case, I just don’t know what that would allow you to do.
Also some people will turn off meta redirects so that it will not work anyway.
i didn’t know of it.
good to know.
it makes sense though. without server side redirects, bots pretty much have to load two pages.
google seem to be in action to reduce their overhead on crawling websites.