WordPress started out as a blog script, but now the most popular plugins are fixing basic problems such as: All in One SEO Pack
Downloaded 14,387,239 times
Contact Form 7
Downloaded 11,038,756 times
Jetpack by WordPress.com
Downloaded 5,306,266 times
W3 Total Cache
Downloaded 2,153,404 times
WordPress Importer
Downloaded 4,721,955 times
WordPress SEO by Yoast
Downloaded 4,757,562 times
Downloaded 14,680,451 times
WooCommerce - excelling eCommerce
Downloaded 915,984 times
Google XML Sitemaps
Downloaded 10,255,289 times
Better WP Security
Downloaded 673,794 times
WP Super Cache
Downloaded 4,576,352 times
Wordfence Security
Downloaded 515,144 times

Really basic things that should be sorted out in the core engine code IMO. Watch out WordPress, better scripts are coming!