The reason most Blogger templates are not SEO friendly because Blogger templates were designed in a long time and have not been updated, probably since 2007, ever since Google SEO algorithm has changed and 'as blogger you do not want t be far away, to keep up with the competition by having your SEO Blogger template is very important and so this short article related to SEO to help you leave behind their competitors.
If you are using a Blogger template, then you need to make some changes to it to meet your needs and to suit the needs of the search engine. Normally search engine focus on important profit margin, but it's a good thing to change it to something user friendly. Blogger templates as' Simple 'Travel', etc have h1 tag as the title of the blog is, what is normal. But the title of the announcement is not correct that everything is in a h3 tag, for many reasons, your blog can not be shown in search results and this is one of those reasons.