Bad Practice

It is bad practice to redirect all 404s to your homepage. The 404 error code exists for a reason: to tell bots and people that the page doesn’t exist. If the page was changed to a new url, you should do a 301 or 302 redirect, but if the page never existed in the first place, then 404 is correct. If the page previously existed but was deleted, then 410. If you redirect all 404s to your homepage, this will confuse bots and visitors and lower your page rank on search engines because they will detect that your site is not set up properly. Be honest about what you are doing; if a page does not exist, tell the user that.