If SEO matters for your blog, and your blog is relevant for users with moble devices, then you pretty much need to enable a mobile template.
Why? In short, because this recent post from Webmaster Central says that for Google the ranking of search results on mobile devices is now impacted by how well sites are optimized for mobile devices.
This means that if you haven't set up your blog for mobile, then it won't come up so highly in the search results seen by mobile users.
As well as the template, there are a range of other factors that affect how well your site works for mobile. Blogger users cannot control a lot of them, though we can think about:
- Page load speed
- Using the Pages gadget as the top menu bar, rather than a linked-list or labels gadget, - because it converts into a drop-down menu in when a mobile template is applied.
Also, remember that if you make a home-page using a custom re-direct, this will only work in your desktop version. The re-direct isn't applied for mobile viewers, they just see your most recent posts in mobile-friendly tiles.
Thanks for reading: Why enabling a mobile template just became more important to some bloggers, Sorry, my English is bad:)